docs: create README.md under typescript/ to showcase list of available packages

[CJ42]

Description

Currently, the typescript/ folder does not contain any README.md file. For a developer, it is hard to clearly visualize which packages are currently available (need to search and navigate through folders)

This PR addresses this issue as follow:

1. create a clean README.md file under the typescript/ folder to:
   • showcase all the available npm package, including their current version (via an npm badge)
   • allow the developer to click on each package name (clickable link) to go directly to the folder and see code examples
   • group packages in tables to differentiate which categories each package belongs to (give a "mental model" to the developer)

2. improve the root README.md file with:
   • top heading Installation (make it more visible at the top)
   • collapsible for each language (Typescript, Python, Go)
   • for Typescript, split into 3 code snippets, so that the developer can just copy directly and paste to install (instead of holding click and swiping through the installation preset he/she wants)

Checklist

• I have formatted and linted my code
• All new and existing tests pass -> Not Applicable
• My commits are signed (required for merge) -- you may need to rebase if you initially pushed unsigned commits
• I added a changelog fragment for user-facing changes (docs-only changes can skip) -> skip