[Infra] Ignore more paths to reduce extraneous builds

[seankimkdy]

I updated our workflows to not run "Build and Test" and "Functional Test Approvals" for PRs that only change some files. The current reasoning behind each (listed under paths-ignore in the diff) is as follows.

• .devcontainer/: Not used in any of the build process, though this may change with #187
• .githooks/: same as above
• docs/: same as above (and already existed before this PR)
• **.md: excludes files such as README, CONTRIBUTING, CODE-OF-CONDUCT
• **.rst: not sure if this isn't covered anywhere that docs/ doesn't cover since we don't use RST outside of docs but just as a safe measure

Resolves #259. @smcclure20 let me know your thoughts.

[github-actions[bot]]

Unit Test Results

304 tests   304 :white_check_mark:  7s :stopwatch:  48 suites    0 :zzz:   1 files      0 :x:

Results for commit 8bfa47c7.

[github-actions[bot]]

For the detailed report, please go to Checks tab, click Build and Test, and then download unit_test_coverage artifact at the bottom of build page.

• Your PR branch coverage: 51.0 %
• main branch coverage: 0 %
• diff coverage: 51.0 %

The coverage result does not include the functional test results.