add machine list to sidebar and home page main listing

This was already in the home page, but not prominent. Makes sense to
have it in the main sidebar, and since those are in sync...

_sidebar.md

@@ -4,6 +4,7 @@
  * [User documentation](doc)
  * [Sysadmin howtos](howto)
  * [Services](service)
+ * [Machine list](https://db.torproject.org/machines.cgi)
  * [Policies](policy)
  * [Meetings](meeting)
  * [Roadmaps](roadmap)

home.md

@@ -12,6 +12,8 @@ The documentation is split into the following sections:
    and the general public
  * [How to](howto) - procedures specifically written for sysadmins
  * [Services](service) - service documentation
+ * [Machine list](https://db.torproject.org/machines.cgi) - the full
+   list of machines managed by TPA (in LDAP)
  * [Policies](policy) - major decisions and how they are made
  * [Meetings](meeting) - minutes from our formal meetings
  * [Roadmaps](roadmap) - documents our plans for the future (and past
@@ -23,9 +25,6 @@ To contact us, see, [how to get help!][]
 
 [how to get help!]: policy/tpa-rfc-2-support#how-to-get-help
 
-For a list of services and which servers they run on check
-[ud-ldap](https://db.torproject.org/machines.cgi).
-
 For our source code, look at [gitweb](https://gitweb.torproject.org/)
 for things under `admin/`.