docs: fix broken links in markdown files

[prajjwol]

Description

Contains fixes for broken links in markdown files and fixes the markdown-link-check action

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For contributor use:

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer

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For admin use:

• Added appropriate labels to PR (ex. WIP, R4R, docs, etc)
• Reviewers assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[prajjwol]

ported it over from: https://github.com/cosmos/cosmos-sdk/blob/9833bf14c1e1388feca724691fe02f0fdac3271c/docs/architecture/PROCESS.md

Not sure why it was missing.