docs: add quick install steps for example (#1029)

More elaborate getting started instructions to help those for who javascript/typescript isn't their primary/secondary environment

---------

Co-authored-by: Erik Janssen <30315129+janssen70@users.noreply.github.com>

README.md

@@ -5,3 +5,7 @@ of video streams and enabling simpler SVG overlays.
 
 For development, you'll need a local installation of [Node.js](https://nodejs.org/),
 and [yarn](https://v3.yarnpkg.com/) to install dependencies.
+To run commands, you need [just](https://just.systems/), which can be installed using
+[prebuilt binaries](https://just.systems/man/en/chapter_5.html#pre-built-binaries) or
+[yarn](https://just.systems/man/en/chapter_8.html#nodejs-installation), e.g.
+`yarn global add just-install`.

example-streams-web/README.md

@@ -14,9 +14,22 @@ examples in one go, combining the different steps explained below.
 
 ## Getting started
 
-To build the project and start serving the examples:
+Make sure you have Node.js installed and `yarn` is available
+(by running `corepack enable` after Node.js installation).
+Supported versions of Node.js are LTS or latest stable.
+
+You also need to install `just` (see main README.md), you can
+do this through the package manager:
+
+```sh
+yarn global add just-install
+```
+
+Then, install dependencies, build the project and start serving the examples:
 
 ```sh
+just install
+just build
 just run example-streams-web
 ```