The Gluon Tunneldigger protocol handler hasn't received the care and
attention a core package, especially a VPN protocol, should.

Due to the works in #2102 it's no longer required to maintain
VPN handlers in the Gluon Core and they can be instead included via a
package feed.

Users who wish to continue using a supported core Gluon package are
encouraged to take a look at fastd in conjunction with it's null@l2tp method.
It offers roughly the same performance (it's using the same principle
of operation) and supports connections via IPv6 as a bonus.

In general it should be possible to change the VPN used protocol
asynchronously with a normal update.

If Gluon users wish to continue using tunneldigger the recomendation
is to participate in the development of tunneldigger inside our
community-packages.

Signed-off-by: Stefan Weil <sw@weilnetz.de>

follow-up on

commit 854fef4e ("docs: consistently indent .rst files with 2 spaces")

A table with hardware supported by Gluon can be found on the OpenWrt Wiki. This commit adds a corresponding FAQ entry.