[docs] Update docs

[m-bert]

Description

In this PR, I go through each section and make sure that everything is in the same style, has correct information and there are no broken links.

Test plan

Read docs 🤓

[Copilot]

Pull request overview

This pull request updates the documentation to ensure consistency in style, correct information, and valid links across multiple sections. The changes improve readability, add helpful internal links, improve organization, and maintain a professional tone throughout the documentation.

Changes:

• Enhanced troubleshooting guide with better organization using tabs for package manager-specific instructions, improved tone and consistency, and added helpful internal links to related documentation
• Restructured testing guide with clearer API documentation format, consolidated information, and updated examples
• Added target="_blank" to external Reanimated link for better user experience

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/docs-gesture-handler/docs/guides/troubleshooting.mdx	Added tab imports, improved professional tone, restructured package manager instructions with Tabs component, and added internal links to Touchables and gesture composition documentation
packages/docs-gesture-handler/docs/guides/testing.md	Restructured API documentation with clearer headers, consolidated parameter descriptions inline, updated example with link to actual test file, and improved formatting
packages/docs-gesture-handler/docs/guides/quickstart/index.md	Added target="_blank" to external Reanimated documentation link
packages/docs-gesture-handler/docs/fundamentals/state-manager.mdx	Added internal link to state documentation
packages/docs-gesture-handler/docs/fundamentals/callbacks-events.mdx	Improved text clarity by removing unnecessary backticks around "Reanimated" and refining sentence structure

Comments suppressed due to low confidence (1)

packages/docs-gesture-handler/docs/guides/troubleshooting.mdx:64

• Inconsistent indentation: This line has extra leading spaces before the bash code block. It should align with the "After that" text above (line 61) at the same indentation level as other content within this TabItem.

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[Copilot]

Grammatical error: "don't have" should be "doesn't have" since "event" is singular.

Suggested change

	- If first event don't have `state` field, the `ACTIVE` state is assumed.
	- If first event doesn't have `state` field, the `ACTIVE` state is assumed.

[m-bert]

This was meant to be done from different branch.

Superseded by #3959