move service template to its correct location

This has been bugging me since basically forever: the howto/template
is not a template for the "howto" section (which is now poorly defined
anyways) at *all*. It's precisely the template for *services*, and
really just belongs there.

I've been hesitant in performing that rename for a long time. First
because GitLab wikis didn't support redirects (they do now, and we add
one here), but also because we probably link to the wiki-replica
version of this in a few places.

I've tried to fix the links inside the wiki, but there are certainly
others that will break. We'll fix those as we go.

For now it seems better and more intuitive to have this at the right
place than preserve the legacy location.

.gitlab/redirects.yml

 ---
 howto/backup: service/backup
+howto/template: service/template
 service/donate-review: service/donate

policy/tpa-rfc-2-support.md

@@ -297,8 +297,8 @@ above.
 
 When a service is adopted by the sysadmin team, the sysadmins will
 make an estimation of costs and resources required to maintain the
-service over time. The documentation should follow the service
-documentation template at [howto/template](howto/template).
+service over time. The documentation should follow the [service
+documentation template](service/template).
 
 There needs to be some commitment by individuals Tor project
 contributors and also by the project that the service will receive

service.md

@@ -6,7 +6,7 @@ This documentation covers all services hosted at TPO.
 
 Every service hosted at TPO should have a documentation page, either
 in this wiki, or elsewhere (but linked here). Services should ideally
-follow this [template](howto/template) to ensure proper documentation.
+follow this [template](service/template) to ensure proper documentation.
 
 ## Internal services
 
@@ -129,7 +129,7 @@ revoked to a LDAP group membership change. In the case of "Puppet",
 it's because the user might have access through that as well.
 
 Every service listed here must have some documentation, ideally
-following the [documentation template](howto/template). As a courtesy,
+following the [documentation template](service/template). As a courtesy,
 TPA allows teams to maintain their documentation in a single page
 here. If the documentation needs to expand beyond that, it should be
 moved to its own wiki, but still linked here.

service/documentation.md

@@ -470,7 +470,7 @@ clicks from the main page. Flat is better than tree.
 All *services* running at torproject.org MUST have a documentation
 page in the [service directory](service) which SHOULD at least include
 a "disaster recovery" and "pager playbook" section. It is strongly
-encouraged to follow the [documentation template](howto/template) for
+encouraged to follow the [documentation template](service/template) for
 new services.
 
 This documentation is based on the [Grand Unified Theory of