[README] [DOCS] A readme for handsontable/examples repository

[scarletfog]

An issue transferred from another repository. original author: @wojciechczerniak

I need a readme and description for this repository.

• Readme
  • Use our template: logo, a short description for the product
  • Then extend with: this repository purpose, maybe files structure, how to contribute a new example
  • One thing we have to figure out is how to version Handsontable within the examples, leave this readme section as a TODO
  • Handsontable logo from handsontable develop branch: https://raw.githubusercontent.com/handsontable/handsontable/develop/resources/handsontable-github-preview.png
• Repository description

Various thoughts:

• It's not going to be published to NPM.
• Each directory contains a project of its own.
• Each project can be run with Codesandbox URL: https://codesandbox.io/s/github/handsontable/examples/tree/master/{path} for example https://codesandbox.io/s/github/handsontable/examples/tree/master/react/basic
• We can list all projects categorized by the framework and link to Codesanbox live example as mentioned above
• But then we will need PR template that has a checklist if the new example was added to the list
• It will be cool to have a small readme template for examples as well. https://github.com/handsontable/examples/tree/master/react/basic Something very basic so an author of a new example doesn't have to focus on this part. A link to live example, maybe a link to the list of examples (main repo page).