Fix a few gtk-doc warnings

Just continuing to chip away at this.

Closes: #788
Approved by: jlebon

src/libostree/ostree-repo.h

@@ -123,6 +123,10 @@ gboolean      ostree_repo_remote_delete (OstreeRepo     *self,
 /**
  * OstreeRepoRemoteChange:
  * The remote change operation.
+ * @OSTREE_REPO_REMOTE_CHANGE_ADD: Add a remote
+ * @OSTREE_REPO_REMOTE_CHANGE_ADD_IF_NOT_EXISTS: Like above, but do nothing if the remote exists
+ * @OSTREE_REPO_REMOTE_CHANGE_DELETE: Delete a remote
+ * @OSTREE_REPO_REMOTE_CHANGE_DELETE_IF_EXISTS: Delete a remote, do nothing if the remote does not exist
  */
 typedef enum {
   OSTREE_REPO_REMOTE_CHANGE_ADD,

src/libostree/ostree-sysroot-deploy.c

@@ -2128,6 +2128,7 @@ ostree_sysroot_deployment_set_kargs (OstreeSysroot     *self,
  * @self: Sysroot
  * @deployment: A deployment
  * @is_mutable: Whether or not deployment's files can be changed
+ * @cancellable: Cancellable
  * @error: Error
  *
  * By default, deployment directories are not mutable.  This function