docs: Update Document for server-side-repo-config.md (runatlantis#4052)

* Update server-side-repo-config.md

Update document for Metric on repo config

* docs(server-side-repo-config): fix case

Co-authored-by: Luke Massa <lukefrederickmassa@gmail.com>

---------

Co-authored-by: Rui Chen <rui@chenrui.dev>
Co-authored-by: Luke Massa <lukefrederickmassa@gmail.com>
Signed-off-by: kvanzuijlen <8818390+kvanzuijlen@users.noreply.github.com>

runatlantis.io/docs/server-side-repo-config.md

@@ -451,6 +451,7 @@ Each servers handle different repository config files.
 | repos     | array[[Repo](#repo)]                                    | see below | no       | List of repos to apply settings to.                                                   |
 | workflows | map[string: [Workflow](custom-workflows.html#workflow)] | see below | no       | Map from workflow name to workflow. Workflows override the default Atlantis commands. |
 | policies  | Policies.                                               | none      | no       | List of policy sets to run and associated metadata                                      |
+| metrics   | Metrics.                                                | none      | no       | Map of metric configuration                                       |
 
 
 ::: tip A Note On Defaults