Changes to docs/installing, including Firefox for Android

[Samq64]

This might still need some work. The installation process is not very user-friendly and tricky to explain.

[WorldLanguages]

There's a few typos

[WorldLanguages]

I still think we could do better on this page, the normal install button for average users can only be found in the navbar.

Maybe we could add big Chrome Web Store and Firefox Addons images just like the extension repo Readme 🤔

I know this is off topic

[Samq64]

Maybe we could add big Chrome Web Store and Firefox Addons images just like the extension repo Readme 🤔

I stuck them at the top of the page.

[Samq64]

I made some more changes. Do you still approve?

[WorldLanguages]

I still don't see the motivation of using web-ext. What's the benefit?

[Samq64]

I still don't see the motivation of using web-ext. What's the benefit?

Mainly that it keeps the extension settings separate from the store release. It also seems to solve the CSS caching issues but I could be wrong.

[hueychen27]

I still don't see the motivation of using web-ext. What's the benefit?

I should have mentioned this, so now I will.
The top 3 benefits:

1. It is a convenient tool used for extension development as it automatically loads the extension to a browser with one command. This means that web-ext is a much improved way of loading an extension with about:debugging.
2. It has features like auto-reloading and linting. Auto-reloading is useful not directly in the webpage but in the extension popup and background services.
3. web-ext creates isolation from the main browser profile by creating a temporary one.

[Samq64]

I reverted the web-ext instructions for desktop. It can be PRed separately.

[hueychen27]

@Samq64 Title change for this pr