improvements to the documentation

[eladyn]

This PR adds the new page that was added in #1030 to the summary, so that it also appears in the sidebar.

It also removes the configuration sections from individual installation pages and replaces them with links to the configuration section. This should make sure that there is more or less a single source of truth regarding the config file.

The "Running as a Service" section was previously a draft page, which was replaced with a proper page shortly summarizing the contents of this chapter.

Closes #1052, since it removes the relevant section.
Fixes #1031 (now points to a section with the correct example config)

[debdrup]

The FreeBSD port/package comes with the rc.d service file necessary to start spotifyd as a service, so if you want to add instructions for how to run as a service on FreeBSD, it's as simple as:

1: Edit config file

2: service spotifyd enable

3: service spotifyd start

[eladyn]

@debdrup Looks like a good suggestion! As I have only little experience with FreeBSD, I'm not really sure how to fit that in here correctly (especially since there seems to be already something similar in the docs). Feel free to open a separate PR for this (or otherwise suggest changes directly to this one)!

[debdrup]

@debdrup Looks like a good suggestion! As I have only little experience with FreeBSD, I'm not really sure how to fit that in here correctly (especially since there seems to be already something similar in the docs). Feel free to open a separate PR for this (or otherwise suggest changes directly to this one)!

I'll be honest, I hadn't seen those docs. 😊

service <entry> enable is just a wrapper around sysrc, so it's perfectly correct to use that over the other.

[SimonTeixidor]

Thanks!