chore: import upstream snapshot with attribution

testing/generation/command_docs/synopses/alter_domain.txt

@@ -0,0 +1,26 @@
+ALTER DOMAIN $name$
+    { SET DEFAULT $expression$ | DROP DEFAULT }
+
+ALTER DOMAIN $name$
+    { SET | DROP } NOT NULL
+
+ALTER DOMAIN $name$
+    ADD $domain_constraint$ [ NOT VALID ]
+
+ALTER DOMAIN $name$
+    DROP CONSTRAINT [ IF EXISTS ] $constraint_name$ [ RESTRICT | CASCADE ]
+
+ALTER DOMAIN $name$
+    RENAME CONSTRAINT $constraint_name$ TO $new_constraint_name$
+
+ALTER DOMAIN $name$
+    VALIDATE CONSTRAINT $constraint_name$
+
+ALTER DOMAIN $name$
+    OWNER TO { $new_owner$ | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
+
+ALTER DOMAIN $name$
+    RENAME TO $new_name$
+
+ALTER DOMAIN $name$
+    SET SCHEMA $new_schema$