New-release

[mcanouil]

What does this PR do?

• iconify - This extension provides shortcodes to Iconify icons library (HTML-based format only).
  Fixes #34
• twitter - This extension provides shortcodes to embed tweets in HTM-based documents.
  Fixes #33
• social-share - This extension allows to add buttons to share HTM-based documents on various social media platforms.
  Fixes #35

Requirements for your Awesome item list

• [x] Only has awesome items. Awesome lists are curations of the best, not everything.
• [x] Does not contain items that are unmaintained, has archived repo, deprecated, or missing docs. If you really need to include such items, they should be in a separate Markdown file.
• [x] Entries have a description, unless the title is descriptive enough by itself. It rarely is though.
• [x] Has consistent formatting and proper spelling/grammar. - The link and description are separated by a dash.
  Example: - [AVA](…) - JavaScript test runner. - The description starts with an uppercase character and ends with a period. - Consistent and correct naming. For example, Node.js, not NodeJS or node.js.
• [x] Doesn't use hard-wrapping.
• [x] Your item(s) fit into an existing sections. (if you think a new section is needed, please open a discussion first).
• [x] Add your new item to the bottom of the list in a section.
• [x] If a duplicate item exists, discuss why the new item should replace it.
• [x] Check your spelling & grammar.
• [x] The item must follow this format:

  - [item name](https link) - Description beginning with capital, ending in period.
  

• [x] Be sure to have read the contributing guidelines.