- explain what happens on gluon-reconfigure
- show workflow to alter the wired network config
- update examples
- update 'has changed in' section

resolves #2474

Co-authored-by: Tom Herbers <mail@tomherbers.de>
Co-authored-by: David Bauer <mail@david-bauer.net>
Co-authored-by: Andreas Ziegler <dev@andreas-ziegler.de>

Co-authored-by: Tom Herbers <mail@tomherbers.de>
Co-authored-by: David Bauer <mail@david-bauer.net>
Co-authored-by: Andreas Ziegler <dev@andreas-ziegler.de>

The OpenLayers JS/CSS download URL is dead. Update it to make the map
work again:

- Update from OpenLayers 5.2.0 to 5.3.0
- Switch from the obsolete rawgit.com URL to jsdelivr.net (rawgit.com
  was only redirecting to jsdelivr.net for the last few years anyways)
- Set a fixed commit in the URL, so the URL doesn't become outdated again

We currently don't have any deprecated devices, so it doesn't make much
sense to force every site to specify this variable. Make it default to 0
instead.

2 spaces is the most common indentation width used in the docs; adjust
the rest for consistency.

Also change .editorconfig accordingly.

Replace occurences of ar71xx with ath79. Remove references of ar71xx
targets which are not relevant anymore.

The map is generated from EUMETNET data, it's source code can be
found at https://gitlab.com/aaaaalbert/wxr-channel-map.

Allow replacing the default OSM layer with a custom XYZ layer in
site.conf.

A microsecond is commonly abbreviated as µs. This prevents confusions
between micro- (µs) and milliseconds (ms).

This adds support for the beacon interval to be set on a per-band base.
This has the potential to reduce the amount of airtime used up for
sending beacon frames.

The 'preserve' flag can be used to mark a peer so it is not removed or
modified on upgrades. In addition, groups containing preserved peers are
not removed.

Fixes: #557

This allows to define a list of packages, which are only installed
for a specific device-class.

This adds documentation for the gluon-mesh-batman-adv package and
elaborates on its build and configuration options, as well as
the implemented multicast architecture.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>

This new build flag is mandatory for now (it may default to 0 in a future
Gluon version). It may be set to the following values:

* 0 - Do not build any images for deprecated devices.
* upgrade - Only build sysupgrade images for deprecated devices.
* full - Build both sysupgrade and factory images for deprecated devices.

"Other" images are handled like factory images, as they are also used for
the initial installation of Gluon on a device.

Add the `wifi5.outdoor_chanlist` site configuration that
allows specifying an outdoor channel range that can be
switched to for regulatory compliance.

Upon enabling the outdoor option the device will
 - configure the `outdoor_chanlist` on all 5 GHz radios
 - which may enable DFS/TPC, based on the regulatory domain
 - disable ibss/mesh on the 5 GHz radio, as DFS *will*
   break mesh connections
 - allow for htmode reconfiguration on 5 GHz radios

The outdoor option can be toggled from
 - Advanced Settings
   - W-LAN
     - Outdoor Installation

The `preserve_channel` flag overrules the outdoor channel
selection.