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>

README.md

@@ -21,7 +21,7 @@ Building Solidity contracts for PolkaVM requires installing the following two co
 
 ### `resolc` binary releases
 
-`resolc` is distributed as a standalone binary (with `solc` as the only external dependency). Please download one of our [binary releases](https://github.com/paritytech/revive/releases) for your target platform and mind the platform specific instructions below. We also provide [nightly builds](https://github.com/paritytech/resolc-bin/tree/main/nightly).
+`resolc` is distributed as a standalone binary (with `solc` as the only external dependency). Please download one of our [binary releases](https://github.com/paritytech/revive/releases) for your target platform and mind the platform specific instructions below. We also provide [nightly builds](https://paritytech.github.io/resolc-bin/#nightly).
 
 <details>
   <summary>MacOS users</summary>
@@ -106,4 +106,3 @@ Please consult the [Developer Guide](https://paritytech.github.io/revive/develop
 
 The revive compiler project, after some early experiments with EVM bytecode translations, decided to fork the `era-compiler` framework.
 [Frontend](https://github.com/matter-labs/era-compiler-solidity), [code generator](https://github.com/matter-labs/era-compiler-llvm-context) and some supporting libraries are based of ZKSync `zksolc`. I'd like to express my gratitude and thank the original authors for providing a useable code base under a generous license.
-