* Fix simple typo: `clearning` -> `learning`

* Update CONTRIBUTING.md

* Add programming languages and frameworks.

* Remove accidentally committed .swp file.

* Added periods to the end of sentences.

This PR adds information on how to resize your images when
contributing.

It also applies a few formatting changes such as:

- Using named links to reduce clutter
- Folding the text at 80 characters for command line users
- Removing dollar signs in codeblocks if no command output is provided
  [MD014][md014]

[md014]: https://github.com/markdownlint/markdownlint/blob/master/docs/RULES.md#md014---dollar-signs-used-before-commands-without-showing-output

Fix typo