Address comments

Added faqs with fees explainer, regtest section from Oli's PR, and several other tweaks

Author: justinpobrien

README.md

@@ -11,9 +11,9 @@ bitcoin into and out of the Lightning Network.
 
 ## Use Cases
 - Automate channel balancing with AutoLoop ([Learn more](https://github.com/lightninglabs/loop/blob/master/docs/autoloop.md))
-- Deposit to a Bitcoin address without closing channels
-- Convert outbound liquidity into inbound liquidity
-- Refill depleted Lightning channels
+- Deposit to a Bitcoin address without closing channels with Loop In
+- Convert outbound liquidity into inbound liquidity with Loop Out
+- Refill depleted Lightning channels with Loop In
 
 ## Installation
 Download the latest binaries from the [releases](https://github.com/lightninglabs/loop/releases) page.
@@ -25,26 +25,14 @@ The Loop client needs its own short-lived daemon to facilitate swaps. To start `
 loopd
 ```
 
-To use Loop in testnet, simply pass the network flag:
-```
-loopd --network=testnet
-```
-
 By default `loopd` attempts to connect to the `lnd` instance running on
 `localhost:10009` and reads the macaroon and tls certificate from `~/.lnd`.
 This can be altered using command line flags. See `loopd --help`.
 
-## LND
-Note that Loop requires `lnd` to be built with **all of its subservers**. Download the latest [official release binary](https://github.com/lightningnetwork/lnd/releases/latest) or build `lnd` from source by following the [installation instructions](https://github.com/lightningnetwork/lnd/blob/master/docs/INSTALL.md). If you choose to build `lnd` from source, use the following command to enable all the relevant subservers:
-
-```
-make install tags="signrpc walletrpc chainrpc invoicesrpc"
-```
-
 ## Usage
 
 ### AutoLoop
-AutoLoop makes it easy to keep your channels balanced. Checkout our [autoloop documentation](https://github.com/lightninglabs/loop/blob/master/docs/autoloop.md) for details.
+AutoLoop makes it easy to keep your channels balanced. Checkout our [autoloop documentation](https://docs.lightning.engineering/advanced-best-practices/advanced-best-practices-overview/autoloop) for details.
 
 ### Loop Out
 Use Loop Out to move bitcoins on Lightning into an on-chain Bitcoin address.
@@ -69,6 +57,37 @@ To execute a Loop In:
 loop in <amt_in_satoshis>
 ```
 
+### More info
+For more information about using Loop checkout our [Loop FAQs](./docs/faqs.md).
+
+## Development
+
+### Regtest
+To get started with local development against a stripped down dummy Loop server
+running in a local `regtest` Bitcoin network, take a look at the
+[`regtest` server environment example documentation](./regtest/README.md).
+
+### Testnet
+To use Loop in testnet, simply pass the network flag:
+```
+loopd --network=testnet
+```
+
+### Submit feature requests
+The [GitHub issue tracker](https://github.com/lightninglabs/loop/issues) can be
+used to request specific improvements or report bugs.
+
+### Join us on Slack
+Join us on the
+[LND Slack](https://lightning.engineering/slack.html) and join the #loop
+channel to ask questions and interact with the community.
+
+## LND
+Note that Loop requires `lnd` to be built with **all of its subservers**. Download the latest [official release binary](https://github.com/lightningnetwork/lnd/releases/latest) or build `lnd` from source by following the [installation instructions](https://github.com/lightningnetwork/lnd/blob/master/docs/INSTALL.md). If you choose to build `lnd` from source, use the following command to enable all the relevant subservers:
+
+```
+make install tags="signrpc walletrpc chainrpc invoicesrpc"
+```
 
 ## API
 The Loop daemon exposes a [gRPC API](https://lightning.engineering/loopapi/#lightning-loop-grpc-api-reference)
@@ -99,9 +118,3 @@ git clone https://github.com/lightninglabs/loop.git
 cd loop/cmd
 go install ./...
 ```
-
-## Development and Support
-The [GitHub issue tracker](https://github.com/lightninglabs/loop/issues) can be
-used to request specific improvements or register and get help with any
-problems. Community support is also available in the
-[LND Slack](https://lightning.engineering/slack.html).

docs/faqs.md

@@ -0,0 +1,61 @@
+
+# Frequently Asked Questions
+
+## How does Loop recover from a crash?
+When `loopd` is terminated (or killed) for whatever reason, it will pickup
+pending swaps after a restart.
+
+Information about pending swaps is stored persistently in the swap database.
+Its location is `~/.loopd/<network>/loop.db`.
+
+## Can Loop handle multiple simultaneous swaps?
+It is possible to execute multiple swaps simultaneously. Just keep loopd
+running.
+
+## What are the fees?
+
+You can pass the `--verbose` flag when using Loop to get a detailed fee
+breakdown
+
+### Loop Out Fees
+
+An explanation of each fee:
+
+- **Estimated on-chain fee**: The estimated cost to sweep the
+  HTLC in case of success, calculated based on the _current_ on-chain fees.
+  This value is called `miner_fee` in the gRPC/REST responses.
+- **Max on-chain fee**: The maximum on-chain fee the daemon
+  is going to allow for sweeping the HTLC in case of success. A fee estimation
+  based on the `--conf_target` flag is always performed before sweeping. The
+  factor of `100` times the estimated fee is applied in case the fees spike
+  between the time the swap is initiated and the time the HTLC can be swept. But
+  that is the absolute worst-case fee that will be paid. If there is no fee
+  spike, a normal, much lower fee will be used.
+- **Max off-chain swap routing fee**: The maximum off-chain
+  routing fee that the daemon should pay when finding a route to pay the
+  Lightning invoice. This is a hard limit. If no route with a lower or equal fee
+  is found, the payment (and the swap) is aborted. This value is calculated
+  statically based on the swap amount (see `maxRoutingFeeBase` and
+  `maxRoutingFeeRate` in `cmd/loop/main.go`).
+- **Max off-chain prepay routing fee**: The maximum off-chain routing
+  fee that the daemon should pay when finding a route to pay the prepay fee.
+  This is a hard limit. If no route with a lower or equal fee is found, the
+  payment (and the swap) is aborted. This value is calculated statically based
+  on the prepay amount (see `maxRoutingFeeBase` and `maxRoutingFeeRate` in
+  `cmd/loop/main.go`).
+- **No show penalty (prepay)**: This is the amount that has to be
+  pre-paid (off-chain) before the server publishes the HTLC on-chain. This is
+  necessary to ensure the server's on-chain fees are paid if the client aborts
+  and never completes the swap _after_ the HTLC has been published on-chain.
+  If the swap completes normally, this amount is counted towards the full swap
+  amount and therefore is actually a pre-payment and not a fee. This value is
+  called `prepay_amt` in the gRPC/REST responses.
+
+### Loop In Fees
+
+An explanation of each fee:
+
+- **Estimated on-chain fee**: The estimated on-chain fee that the
+  daemon has to pay to publish the HTLC. This is an estimation from `lnd`'s
+  wallet based on the available UTXOs and current network fees. This value is
+  called `miner_fee` in the gRPC/REST responses.