Merge docs/maintenance-checking-services.md to docs/maintenance-and-troubleshooting.md

IMHO it seems to be sensible to concentrate details about maintenance at one documentation page for the sake of maintainability, rather than maintaining pages with a single short section.

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

CHANGELOG.md

@@ -3344,7 +3344,7 @@ Due to changes related to certificate file requirements that will affect us at S
 
 **What you need to do now** is make use of this transitional Synapse v0.99 release to **prepare your federation settings for the future**. You have 2 choices to prepare yourself for compatibility with the future Synapse v1.0:
 
-- (recommended) set up [Server Delegation via a well-known file](docs/howto-server-delegation.md#server-delegation-via-a-well-known-file), unless you are affected by the [Downsides of well-known-based Server Delegation](docs/howto-server-delegation.md#downsides-of-well-known-based-server-delegation). If you had previously set up the well-known `client` file, depending on how you've done it, it may be that there is nothing new required of you (besides [upgrading](docs/maintenance-upgrading-services.md)). After upgrading, you can [run a self-check](docs/maintenance-checking-services.md), which will tell you if you need to do anything extra with regard to setting up [Server Delegation via a well-known file](docs/howto-server-delegation.md#server-delegation-via-a-well-known-file). After some time, when most people have upgraded to Synapse v0.99 and older releases have disappeared, be prepared to drop your `_matrix._tcp` SRV record.
+- (recommended) set up [Server Delegation via a well-known file](docs/howto-server-delegation.md#server-delegation-via-a-well-known-file), unless you are affected by the [Downsides of well-known-based Server Delegation](docs/howto-server-delegation.md#downsides-of-well-known-based-server-delegation). If you had previously set up the well-known `client` file, depending on how you've done it, it may be that there is nothing new required of you (besides [upgrading](docs/maintenance-upgrading-services.md)). After upgrading, you can [run a self-check](docs/maintenance-and-troubleshooting.md#how-to-check-if-services-work), which will tell you if you need to do anything extra with regard to setting up [Server Delegation via a well-known file](docs/howto-server-delegation.md#server-delegation-via-a-well-known-file). After some time, when most people have upgraded to Synapse v0.99 and older releases have disappeared, be prepared to drop your `_matrix._tcp` SRV record.
 
 - (more advanced) if the [Downsides of well-known-based Server Delegation](docs/howto-server-delegation.md#downsides-of-well-known-based-server-delegation) are not to your liking, **as an alternative**, you can set up [Server Delegation via a DNS SRV record](docs/howto-server-delegation.md#server-delegation-via-a-dns-srv-record-advanced). In such a case, you get to keep using your existing `_matrix._tcp` DNS SRV record forever and need to NOT set up a `/.well-known/matrix/server` file. Don't forget that you need to do certificate changes though. Follow the guide at [Server Delegation via a DNS SRV record](docs/howto-server-delegation.md#server-delegation-via-a-dns-srv-record-advanced).
 
@@ -3661,7 +3661,7 @@ From now on, Riot's configuration setting `disable_guests` would be set to `true
 
 ## Self-check maintenance command
 
-The playbook can now [check if services are configured correctly](docs/maintenance-checking-services.md).
+The playbook can now [check if services are configured correctly](docs/maintenance-and-troubleshooting.md#how-to-check-if-services-work).
 
 
 # 2018-10-05