install.md: improved docs for "customizing paths" section

[Ser5]

More structured and detailed text:

• at the top are general description of Flarum config files that will be used further
• then common cases of custom paths

[Ser5]

Please note that the text may be incorrect as I didn't test it thoroughly - I have been using only my third solution, one with symlinks, works nicely. Also it makes no-public-dir archives and Apache/Nginx configs obsolete. You may wish to rewrite/update the entire page accordingly.

Also English isn't my native language, so some sentences may sound clunky.

[luceos]

Although I think your changes make a lot of sense, they assume a couple of things that might not be available to all users.

Our public path installation instructions are kept simple for many reasons, for one we do not assume a separate directory is available outside the public path to install the "engine" into.

Secondly your instructions seem to mix the engine path naming a few times, the fact that it's hard to understand what is what already makes it hard to read, I am not comfortable showing this level of complexity to new users with zero server knowledge.

I agree that the page needs some better instructions, clarifications why certain things are necessary for instance, and your PR is a good starting point to look at what areas to improve. But I don't think we should merge this as is.

I hope you understand, and are willing to keep the PR open so we can improve our documentation based on it at a later point in time.

Thank you so much for your contribution and I wish you a fantastic 2025.

[Ser5]

Oh hi there! Thank you for the review! When writing my version I already was sure that it will hardly match guidelines of your docs, terminology, etc. After all, a random dude out from nowhere can't magically understand all the ideas your team has been working on for years. So yes, I fully agree that my PR shouldn't be bluntly merged, it's but a suggestion, that you can drag some ideas from.

Thank you so much for your contribution and I wish you a fantastic 2025.

Wowowow, cool! Thanks a lot! I wish you the best too!