Link to crates.io to get $VERSION (payjoin#608)

Adds a link in the `payjoin-cli` README to the `payjoin-cli` crates.io
page to allow anyone following the README instructions to easily find
the latest usable version. I suppose we could also use this url to be
even more explicit if we choose:
[https://crates.io/crates/payjoin-cli/versions](https://crates.io/crates/payjoin-cli/versions).

Also changes "payjoin-cli" references to render as `payjoin-cli` (an
opinionated change I'll admit).

Closes payjoin#595

Author: DanGould

payjoin-cli/README.md

@@ -1,27 +1,27 @@
-# payjoin-cli
+# `payjoin-cli`
 
-## A command-line payjoin client for bitcoind in rust
+## A command-line payjoin client for bitcoind in Rust
 
 The `payjoin-cli` client enables sending and receiving of [BIP 78 Payjoin V1](https://github.com/bitcoin/bips/blob/master/bip-0078.mediawiki) and [Draft BIP Payjoin V2](https://github.com/bitcoin/bips/pull/1483) transactions. By default it supports Payjoin V1, and the `v2` feature sends and receives both since the protocol is backwards compatible. The implementation is built on [Payjoin Dev Kit](https://payjoindevkit.org).
 
 While this code and design has had significant testing, it is still alpha-quality experimental software. Use at your own risk.
 Independent audit is welcome.
 
-## Install payjoin-cli
+## Install `payjoin-cli`
 
 ```console
 cargo install payjoin-cli --version $VERSION
 ```
 
-where `$VERSION` is the latest version of the payjoin-cli you wish to install.
+where `$VERSION` is the [latest version](https://crates.io/crates/payjoin-cli) of the `payjoin-cli` you wish to install.
 
 Get a list of commands and options:
 
 ```console
 payjoin-cli --help
 ```
 
-Either pass config options from cli, or manually edit a `config.toml` file within directory you run payjoin-cli from.
+Either pass config options from cli, or manually edit a `config.toml` file within directory you run `payjoin-cli` from.
 Configure it like so:
 
 ```toml
@@ -35,7 +35,7 @@ Your configuration details will vary, but you may use this as a template.
 
 ## Test Payjoin 2
 
-### Install payjoin-cli with the V2 feature
+### Install `payjoin-cli` with the V2 feature
 
 ```console
 cargo install payjoin-cli --version $VERSION --features v2
@@ -57,7 +57,7 @@ ohttp_relay="https://pj.bobspacebkk.com"
 
 ### Asynchronous Operation
 
-Send and receiver state is saved to a database in the directory from which payjoin-cli is run. Once a send or receive session is started, it may resume using the `resume` argument if prior payjoin sessions have not yet complete.
+Send and receiver state is saved to a database in the directory from which `payjoin-cli` is run. Once a send or receive session is started, it may resume using the `resume` argument if prior payjoin sessions have not yet complete.
 
 ```console
 payjoin-cli resume
@@ -76,7 +76,7 @@ file. 18443 is the default. This can be set like so:
 rpcport = 18443
 ```
 
-From the directory you'll run payjoin-cli, assuming "boom" is the name of the receiving wallet, 18443 is the rpc port, and you wish to request 10,000 sats run:
+From the directory you'll run `payjoin-cli`, assuming "boom" is the name of the receiving wallet, 18443 is the rpc port, and you wish to request 10,000 sats run:
 
 ```console
 RUST_LOG=debug cargo run --features=_danger-local-https -- -r "http://localhost:18443/wallet/boom" receive 10000
@@ -93,7 +93,7 @@ BITCOIN:BCRT1QCJ4X75DUNY4X5NAWLM3CR8MALM9YAUYWWEWKWL?amount=0.00010&pj=https://l
 
 ### Test Send
 
-Create a "sender" directory within payjoin-cli. Open a new terminal window and navigate to this directory.
+Create a "sender" directory within `payjoin-cli`. Open a new terminal window and navigate to this directory.
 
 Note: A wallet cannot payjoin with itself, one needs separate wallets.