Remove trailing whitespace in markdown

[robert-zaremba]

Summary

Leaving trailing an whitespace in a code causes useless diffs. It's also not good for a code style.

• make lint should fail if there are trailing whitespaces
• make lint-fix should remove trailing whitespaces

Problem Definition

#8107 (review)

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For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned

[tac0turtle]

this seems specific to markdown not code, am I missing something?

[alexanderbez]

I think @robert-zaremba means the markdown file(s). Yah, we should have a linter. It's annoying to keep fixing these in PRs.

[tac0turtle]

On tendermint we use githubs super linter: https://github.com/tendermint/tendermint/blob/master/.github/workflows/linter.yml with markdown linting.

[alessio]

@marbar3778 does that just raise warnings? Could it fix them too?

[tac0turtle]

raise warnings, we use https://github.com/igorshubovych/markdownlint-cli to fix them