Docs: WFS and Style

[JakobMiksch]

• add docs for WFS
• add docs for Style including Labels
• make mandatory properties bold and remove column "mandatory". This makes the docs less verbose.
• Update the version number

TODO:

• add remark that bold properties are mandatory

[chrismayer]

Thanks for this. I added some points, which should be addressed before merging.

[justb4]

Good to have mandatory attrs in bold! Is it an idea to also add a default column for non-mandatory attrs (where applicable)? This is often expressed in the 'meaning' text.

[JakobMiksch]

@justb4 I like the idea of having a column for default values. I do not see this change in this PR, but I will open an issue: #161

[chrismayer]

This is good to go, thanks @JakobMiksch! I'll merge now.