(maint) Fix broken links to discussions/issues/PRs in README

[sryze]

Description

Fixed a few links to repository pages inside the README such as Discussions, Issues, Pull Requests. Also fixed a typo.

GitHub treats relative links as relative to repo's code root directory, so discussions becomes blob/master/discussions instead of the intended page. One common workaround is to use a relative path that goes back 2 levels like ../../discussions.

Motivation and Context

How Has this Been Tested?

Screenshot (if appropriate, usually isn't needed):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Migrated package (a package has been migrated from another repository)

Checklist:

• My code follows the code style of this repository.
• My change requires a change to documentation (this usually means the notes in the description of a package).
• I have updated the documentation accordingly (this usually means the notes in the description of a package).
• I have updated the package description and it is less than 4000 characters.
• All files are up to date with the latest Contributing Guidelines
• The added/modified package passed install/uninstall in the Chocolatey Test Environment(https://github.com/chocolatey-community/chocolatey-test-environment/). Note that we don't support the use of any other environment.
• The changes only affect a single package (not including meta package).

[AppVeyorBot]

✅ Package verification completed without issues. PR is now pending human review

[AppVeyorBot]

✅ Package verification completed without issues. PR is now pending human review

[AdmiringWorm]

LGTM

[AdmiringWorm]

@sryze thanks for getting those links updated 👍