docs: improve readability with additional subheaders

[pengooseDev]

Description

Following #33138

• Improved readability by adding subheaders in the "Make a change" section of the contribution guide.
• Grouped TypeScript Type Generation and Write documentation for better accessibility.

---

Additionally, I wonder if moving the Linting section to the end of ## Make a change would improve the flow. (> link)
Since functional changes often impact types, placing TypeScript Type Generation and Write documentation together might enhance accessibility.

I would appreciate feedback. If there are any changes needed, I'm happy to make them. :)

[github-actions[bot]]

Test results for "tests 1"

2 flaky

:warning: [firefox-library] › library/browsercontext-reuse.spec.ts:86:1 › should reset serviceworker that hangs in importScripts @firefox-ubuntu-22.04-node18
:warning: [chromium-page] › page/page-event-request.spec.ts:110:3 › should report navigation requests and responses handled by service worker @ubuntu-20.04-chromium-tip-of-tree

36308 passed, 639 skipped :heavy_check_mark::heavy_check_mark::heavy_check_mark:

Merge workflow run.

[github-actions[bot]]

Test results for "tests 1"

2 flaky

:warning: [chromium-library] › library/popup.spec.ts:264:3 › should not throw when click closes popup @ubuntu-20.04-chromium-tip-of-tree
:warning: [chromium-library] › library/trace-viewer.spec.ts:674:1 › should handle src=blob @ubuntu-20.04-chromium-tip-of-tree

36392 passed, 639 skipped :heavy_check_mark::heavy_check_mark::heavy_check_mark:

Merge workflow run.

[github-actions[bot]]

Test results for "tests 1"

4 flaky

:warning: [playwright-test] › ui-mode-test-setup.spec.ts:98:5 › should show errors in config @macos-latest-node18-1
:warning: [installation tests] › playwright-electron-should-work.spec.ts:21:5 › electron should work @package-installations-macos-latest
:warning: [webkit-library] › library/screenshot.spec.ts:64:14 › page screenshot › should work with a mobile viewport and fullPage @webkit-ubuntu-22.04-node18
:warning: [webkit-library] › library/screenshot.spec.ts:217:14 › element screenshot › element screenshot should work with device scale factor @webkit-ubuntu-22.04-node18

36395 passed, 639 skipped :heavy_check_mark::heavy_check_mark::heavy_check_mark:

Merge workflow run.

[github-actions[bot]]

Test results for "tests 1"

1 flaky

:warning: [webkit-library] › library/browsercontext-add-cookies.spec.ts:429:3 › should allow unnamed cookies @webkit-ubuntu-22.04-node18

35085 passed, 618 skipped :heavy_check_mark::heavy_check_mark::heavy_check_mark:

Merge workflow run.

[github-actions[bot]]

Test results for "tests 1"

2 flaky

:warning: [webkit-library] › library/browsercontext-viewport-mobile.spec.ts:116:5 › mobile viewport › default mobile viewports to 980 width @webkit-ubuntu-22.04-node18
:warning: [webkit-library] › library/screenshot.spec.ts:94:14 › page screenshot › should work with device scale factor and scale:css @webkit-ubuntu-22.04-node18

36433 passed, 639 skipped :heavy_check_mark::heavy_check_mark::heavy_check_mark:

Merge workflow run.