Show binary releases details on resolc-bin GH Pages site (#447)

## Description

For more easily finding the details of the resolc binary releases for
the various supported platforms, the plain JSON information will be
displayed on [resolc-bin](https://github.com/paritytech/resolc-bin)'s
[GitHub Pages website](https://paritytech.github.io/resolc-bin/).

Changes:
* Whenever there is a regular or nightly release:
* The corresponding workflow files will run a script to update
resolc-bin's `index.md` file (new file) with the updated JSON.
* `index.md` will be the file GitHub Pages serves as HTML (by default it
is built with Jekyll and the Markdown is processed by kramdown, hence
the syntax seen in the script).
* Documentation  updates

Thus, this will run on the next nightly release after this PR is merged.

## Resolved Issues

Closes #443

---------

Co-authored-by: xermicus <cyrill@parity.io>

RELEASE.md

@@ -14,8 +14,8 @@ To create a new pre-release:
 4. The release workflow will attempt to build and publish a new pre-release if the latest tag does match the cargo package version.
 5. Wait for the `Release` workflow to finish. It should create the pre-release with the same name.
 6. Check that pre-release was created on the [Releases page](https://github.com/paritytech/revive/releases) with all artifacts.
-7. After the release is published, another workflow should start automatically and update json files in https://github.com/paritytech/resolc-bin. Check the changes.
-8. Update the [contract-docs](https://github.com/paritytech/contract-docs/) accordingly
+7. After the release is published, another workflow should start automatically and update JSON files in the [resolc-bin repository](https://github.com/paritytech/resolc-bin) as well as render the JSON on its [GitHub Pages website](https://paritytech.github.io/resolc-bin/). Check the changes.
+8. Update the [revive compiler book](https://github.com/paritytech/revive/tree/main/book) accordingly.
 
 # `resolc` NPM package release