Markdown Linting Github Action

[VijaySharma815]

VS code extension:
https://marketplace.visualstudio.com/items?itemName=DavidAnson.vscode-markdownlint

Rules:
https://github.com/DavidAnson/markdownlint/blob/v0.25.1/doc/Rules.md

Md linting tool:
https://github.com/DavidAnson/markdownlint

GitHub actions:
https://github.com/avto-dev/markdown-lint

[github-actions]

Visit the preview URL for this PR (updated for commit e16ab62):

https://fetch-docs-preview--pr250-feat-md-linting-acti-vjfm0vlx.web.app

_{(expires Wed, 14 Sep 2022 17:33:38 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

[5A11]

lgtm

Missed CI failure

[5A11]

@VijaySharma815 please address the CI failures.

[5A11]

Add automated listing of markdown files in the script that generates the reference API.
Add automated listing of markdown files in MakeFile as a separate command and as part of make lint.

[VijaySharma815]

I found the python package but it's inactive:
https://github.com/jorisroovers/pymarkdownlint

also, it uses click 4.1 which is incompatible with many of our library:

ERROR: safety 2.1.1 has requirement Click>=8.0.2, but you'll have click 4.1 which is incompatible.
ERROR: pydoc-markdown 4.6.3 has requirement click<9.0,>=7.1, but you'll have click 4.1 which is incompatible.
ERROR: mkdocs 1.3.1 has requirement Markdown<3.4,>=3.2.1, but you'll have markdown 3.4.1 which is incompatible.
ERROR: black 22.6.0 has requirement click>=8.0.0, but you'll have click 4.1 which is incompatible.

[VijaySharma815]

@5A11 In this PR I already did linting:
https://github.com/fetchai/cosmpy/pull/180/files

[solarw]

@VijaySharma815
please take a look.
#279

make docs-check and make docs-format commands are added
md files are not formatted, so please take a look is auto formatting good for you

[5A11]

This tool requires the introduction of a heavy dependency, either npm and associated JS dependencies, or docker. For such an optional tool, such a move is not justified.

For now, a standard python tool is preferred.