docs: improve English, Markdown, and clarity in README

[dandv]

Priority*

• Medium: This PR should be merged quickly to prevent conflicts due to common changes.

Purpose of the PR*

Thank you for publishing this boilerplate! As a new user, I was mindful of the onboarding process and I contributed a number of fixes that should help future users get started faster and with more clarity as to what various pars of the boilerplate do.

Changes*

• explain how to change the extension version
• add warning about restricting permissions to respect users' privacy in production
• clarify pages usage
• fix English grammar in sections I had to understand in order to use the boilerplate (this doesn't mean that unchanged sections are correct; just that I didn't get to change them, or that they were too confusing at this stage - see Notes
• update Chrome Extensions URLs (many pointed to mv3)
• link pages to their directories
• remove superfluous Markdown section anchors that are generated automatically by GitHub with the same a name
• fix abused Markdown formatting with more appropriate version
• reordered References section with the Chrome Extensions first; Vite is an implementation details of secondary importance

Notes

Some aspects that could be further clarified:

1. What is the difference between the content and content-ui pages?
2. Why are some files repeated, e.g. pages/content/public/logo.svg is also found in /pages/content-ui/public/logo.svg
3. The "Install dependency for turborepo" section. New users may not be familiar with Turborepo, and even after reading about it, it seems like an implementation detail, yet here it gets an entire section. What exactly are "for root" and "for module" in that section?
4. The "TIP" about sharing state seems to belong towards the end of the page; it's a detail rather than the main screenshot for the boilerplate. It could be replaced with a screenshot showing most of the features at the same time (content script UI at the bottom of a page, the side panel, the action pop-up, a new tab in a separate window)

[Jonghakseo]

Thank you for the many corrections and suggestions to the documentation.
I'll make sure to add clarity where it's needed(including you mentioned).

[Jonghakseo]

As a non-native English speaker, I am very happy to have this help.
Thank you very much.

[dandv]

More than happy to help! I'm not a native speaker either :)