chore(AIP-129): fix formatting of list (#1291)

Author: macjohnny

aip/general/0129.md

@@ -41,6 +41,7 @@ Some examples of these types of fields are ones that are:
 
 An attribute with an effective value ***must*** be expressed as two fields in
 the API:
+
 * a mutable field that can be optionally set by the user and **must not** be
 modified by the service
 * an `OUTPUT_ONLY` field that records the effective value decided on by the
@@ -145,4 +146,4 @@ service to validate it was set correctly.
 <!-- prettier-ignore-start -->
 [aip-180]: ./0180.md
 [state-driven-clients]: ./009.md#state-driven-clients
-<!-- prettier-ignore-end -->
+<!-- prettier-ignore-end -->