Move test tips to contributing doc

CONTRIBUTING.md

@@ -163,6 +163,8 @@ was broken. They are slower than the linters but will typically catch more error
 ```sh
 source ./env/bin/activate
 trial tests
+# The tests can also be run with this longer command
+python -m twisted.trial tests
 ```
 
 If you wish to only run *some* unit tests, you may specify
@@ -179,6 +181,14 @@ If your tests fail, you may wish to look at the logs:
 less _trial_temp/test.log
 ```
 
+To see always see logger output from the app while the tests run,
+set `SYNAPSE_TEST_LOG_LEVEL` and the resulting logs will be in `_trial_temp/test.log`:
+
+```sh
+SYNAPSE_TEST_LOG_LEVEL=DEBUG trial tests
+```
+
+
 ## Run the integration tests.
 
 The integration tests are a more comprehensive suite of tests. They

README.rst

@@ -327,15 +327,8 @@ differ)::
 
     PASSED (skips=15, successes=1322)
 
-To run a specific test::
-
-    python -m twisted.trial tests.storage.test_redaction
-    python -m twisted.trial tests.handlers.test_presence.PresenceJoinTestCase.test_remote_gets_presence_when_local_user_joins
-
-To see logger output from the app while the tests run, set ``SYNAPSE_TEST_LOG_LEVEL``
-and the resulting logs will be in ``_trial_temp/test.log``::
-
-    SYNAPSE_TEST_LOG_LEVEL=DEBUG python -m twisted.trial tests
+For more tips on running the unit tests, like running a specific test or
+show the logger output of the app, see the `CONTRIBUTING doc <CONTRIBUTING.md#run-the-unit-tests>`_.
 
 
 Running the Integration Tests