Documenting common pitfalls

[alexwilson]

Continuing on from #827...

Right now, while not strictly an issue regarding this repository, there's at the very least a common pitfall wherein without a correctly configured Symfony application + reverse proxy, we'll generate links with the wrong scheme (as we utilise Symfony's Request class).

I'm not sure if there are any other obvious ones, but I am thinking to remedy this we should start looking at building a FAQ?

[greg0ire]

Either a FAQ or maybe augment the web path resolver docs? That's the class where I found this piece of logic. Things to document : how it uses the request context, put a link to the symfony docs about the trusted proxies, but also maybe to the page about the request context itself in case this class is somehow used from the CLI context at some point (no idea if it is actually the case)

[cedricziel]

I like the idea of adding the pitfalls to the web path resolver docs, since other resolvers (may) have their own ways of obtaining the correct path for their referenced assets. (think of flysystem for example)

[robfrawley]

All for improving the docs! For those not comfortable with RST, feel free to post the information you'd like added here and I'll be happy to push it into our RST documentation.

[greg0ire]

I went ahead and made #829 . Please review.