* Add markdown linting

- add linter default rules
- adapt rules to current code
- fix the code for linting to pass
- add CI check

fix #1243

* Fix markdown for Substrate
* Fix tooling install
* Fix workflow
* Add documentation
* Remove trailing spaces
* Update .github/.markdownlint.yaml

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
* Fix mangled markdown/lists
* Fix captalization issues on known words

* Added root README.md draft

* Modified Contribution section to reflect unified guidelines

* Update README.md

Co-authored-by: Squirrel <gilescope@gmail.com>

* Expand Substrate description

* Added Badges and Upstream deps

* Fixed badge links

* Fixed CONTRIBUTING.md links, added security and resources section to root README.md

* Moved runtimes link to Polkadot section

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Co-authored-by: Squirrel <gilescope@gmail.com>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* add link to labels doc

* add absolute links in PR template

* Update docs/CONTRIBUTING.md

* update contribution guidelines, remove redundant files

* removing doc ref labels, updating links on contribution

* add manifest formatting

* update title

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* update links to the new repo

* terminal friendly convention

* update doc guideline format

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Co-authored-by: Alexander Samusev <41779041+alvicsam@users.noreply.github.com>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>