remove dead web clients

See merge request !12

See https://github.com/pump-io/pump.io/issues/1685

See https://github.com/pump-io/pump.io/issues/1685

Since admins are likely to run into this one first.

A user thought this meant the machine hostname, as reported by
`hostname`.

Still needs a fair bit of work.

These are doing more harm than good; see #17

Squashes the last Sphinx warning.

This squashes a bunch of warnings. Squashing all those spurious
warnings also made it easier to see a legitimate warning, which was
that the installation channel documentation wasn't accessible from
anywhere. This is now also fixed.

The "Installation" section also got reordered a little bit.

This got lost in the conversion to a table format.

Fixes #22

Ref #1, although this isn't exactly what that issue was about.

Fixes #15

Closes #11

Thanks to Jason Self for writing this up.

See #11

Ref #21

Fixes #18

Fixes #19

Closes #16

See merge request !9