Add ch-ua-form-factors to list of policy-controlled features (#162)

Fixes #161

index.bs

@@ -118,7 +118,7 @@ following specifications and proposals:
             same-origin or delegated-to cross-origin requests. It also makes sure
             hints are removed from not delegated-to cross-origin requests after
             redirections.
-     - Defines the `Critical-CH` response header, which servers may use to request a restart	
+     - Defines the `Critical-CH` response header, which servers may use to request a restart
          to include critical Client Hints missing in the initial load.
      - Integrates those concepts with the [[!HTML]] and [[!FETCH]] specifications,
          by patching various concepts there.
@@ -445,6 +445,7 @@ the following [=policy-controlled features=]:
 - <code><dfn export>ch-ua</dfn></code> which has a [=default allowlist=] of `'*'`
 - <code><dfn export>ch-ua-arch</dfn></code> which has a [=default allowlist=] of `'self'`
 - <code><dfn export>ch-ua-bitness</dfn></code> which has a [=default allowlist=] of `'self'`
+- <code><dfn export>ch-ua-form-factors</dfn></code> which has a [=default allowlist=] of `'self'`
 - <code><dfn export>ch-ua-full-version</dfn></code> which has a [=default allowlist=] of `'self'`
 - <code><dfn export>ch-ua-full-version-list</dfn></code> which has a [=default allowlist=] of `'self'`
 - <code><dfn export>ch-ua-mobile</dfn></code> which has a [=default allowlist=] of `'*'`