Update readme to reflect latest config.json and matrix-js-sdk dependency (#3028)

Author: hughns

README.md

@@ -22,7 +22,7 @@ development version continuously deployed to
 Until prebuilt tarballs are available, you'll need to build Element Call from
 source. First, clone and install the package:
 
-```
+```sh
 git clone https://github.com/element-hq/element-call.git
 cd element-call
 yarn
@@ -33,21 +33,22 @@ If all went well, you can now find the build output under `dist` as a series of
 static files. These can be hosted using any web server that can be configured
 with custom routes (see below).
 
-You may also wish to add a configuration file (Element Call uses the domain it's
-hosted on as a Homeserver URL by default, but you can change this in the config
-file). This goes in `public/config.json` - you can use the sample as a starting
-point:
+You also need to add a configuration file which goes in `public/config.json` -
+you can use the sample as a starting point:
 
-```
+```sh
 cp config/config.sample.json public/config.json
 # edit public/config.json
 ```
 
+The sample needs editing to contain the homeserver and LiveKit backend that you
+are using.
+
 Because Element Call uses client-side routing, your server must be able to route
 any requests to non-existing paths back to `/index.html`. For example, in Nginx
 you can achieve this with the `try_files` directive:
 
-```
+```jsonc
 server {
     ...
     location / {
@@ -57,12 +58,6 @@ server {
 }
 ```
 
-By default, the app expects you to have a Matrix homeserver (such as
-[Synapse](https://element-hq.github.io/synapse/latest/setup/installation.html))
-installed locally and running on port 8008. If you wish to use a homeserver on a
-different URL or one that is hosted on a different server, you can add a config
-file as above, and include the homeserver URL that you'd like to use.
-
 Element Call requires a homeserver with registration enabled without any 3pid or
 token requirements, if you want it to be used by unregistered users.
 Furthermore, it is not recommended to use it with an existing homeserver where
@@ -88,13 +83,13 @@ If you're using [Synapse](https://github.com/element-hq/synapse/), you'll need
 to additionally add the following to `homeserver.yaml` or Element Call won't
 work:
 
-```
+```yaml
 experimental_features:
-    # MSC3266: Room summary API. Used for knocking over federation
-    msc3266_enabled: true
-    # MSC4222 needed for syncv2 state_after. This allow clients to
-    # correctly track the state of the room.
-    msc4222_enabled: true
+  # MSC3266: Room summary API. Used for knocking over federation
+  msc3266_enabled: true
+  # MSC4222 needed for syncv2 state_after. This allow clients to
+  # correctly track the state of the room.
+  msc4222_enabled: true
 
 # The maximum allowed duration by which sent events can be delayed, as
 # per MSC4140.
@@ -152,38 +147,25 @@ discuss and coordinate translation efforts.
 
 ### Frontend
 
-Element Call is built against
-[matrix-js-sdk](https://github.com/matrix-org/matrix-js-sdk/pull/2553). To get
-started, clone, install, and link the package:
+To get started clone and set up this project:
 
-```
-git clone https://github.com/matrix-org/matrix-js-sdk.git
-cd matrix-js-sdk
-yarn
-yarn link
-```
-
-Next, we can set up this project:
-
-```
+```sh
 git clone https://github.com/element-hq/element-call.git
 cd element-call
 yarn
-yarn link matrix-js-sdk
 ```
 
-To use it, create a local config by, e.g., `cp ./config/config.devenv.json
-./public/config.json` and adapt it if necessary. The `config.devenv.json` config
-should work with the backend development environment as outlined in the next
-section out of box.
+To use it, create a local config by, e.g., `cp ./config/config.devenv.json ./public/config.json`
+and adapt it if necessary. The `config.devenv.json` config should work with the backend
+development environment as outlined in the next section out of box.
 
 (Be aware, that this `config.devenv.json` is exposing a deprecated fallback
 LiveKit config key. If the homeserver advertises SFU backend via
 `.well-known/matrix/client` this has precedence.)
 
 You're now ready to launch the development server:
 
-```
+```sh
 yarn dev
 ```
 
@@ -192,19 +174,19 @@ yarn dev
 A docker compose file `dev-backend-docker-compose.yml` is provided to start the
 whole stack of components which is required for a local development environment:
 
-- Minimum Synapse Setup (servername: synapse.localhost)
+- Minimum Synapse Setup (servername: `synapse.localhost`)
 - LiveKit JWT Service (Note requires Federation API and hence a TLS reverse proxy)
-- Minimum TLS reverse proxy (servername: synapse.localhost) Note certificates
+- Minimum TLS reverse proxy (servername: `synapse.localhost`) Note certificates
   are valid for at least 10 years from now
 - Minimum LiveKit SFU Setup using dev defaults for config
-- Redis db for completness
+- Redis db for completeness
 
 These use a test 'secret' published in this repository, so this must be used
 only for local development and **_never be exposed to the public Internet._**
 
 Run backend components:
 
-```
+```sh
 yarn backend
 # or  for podman-compose
 # podman-compose -f dev-backend-docker-compose.yml up
@@ -221,13 +203,15 @@ To add a new translation key you can do these steps:
 1. Add the new key entry to the code where the new key is used: `t("some_new_key")`
 1. Run `yarn i18n` to extract the new key and update the translation files. This
    will add a skeleton entry to the `locales/en/app.json` file:
+
    ```jsonc
    {
        ...
        "some_new_key": "",
        ...
    }
    ```
+
 1. Update the skeleton entry in the `locales/en/app.json` file with
    the English translation: