[Documentation] Document pre-merge testing

CONTRIBUTING.md

@@ -292,6 +292,7 @@ checklist.)
 2. Unit tests included and/or updated with changes?
 3. Command line build passes?
 4. Expect to pass code review?
+5. Changes have been smoke-tested?
 
 ### Reviewer Checklist
 

docs/src/process/testing/plan.md

@@ -2,18 +2,41 @@
 
 ## Test Levels
 
-Testing occurs regularly during development, with varying levels of
-completeness.
+Testing for Open MCT Web includes:
 
-In order of decreasing frequency and increasing completeness, these
-are:
+* _Smoke testing_: Brief, informal testing to verify that no major issues
+  or regressions are present in the software, or in specific features of
+  the software.
+* _Unit testing_: Automated verification of the performance of individual
+  software components.
+* _User testing_: Testing with a representative user base to verify
+  that application behaves usably and as specified.
+* _Long-duration testing_: Testing which takes place over a long period
+  of time to detect issues which are not readily noticeable during
+  shorter test periods.
 
-1. __Pre-merge testing__: Performed before changes are integrated
-   into the software.
-2. __Partial acceptance testing__: A subset of acceptance testing
-   performed at regular intervals.
-3. __Acceptance testing__: Performed before a new release is considered
-   stable.
+### Smoke Testing
 
-Each level of testing is inclusive of the levels which proceed it.
+### Unit Testing
 
+### User Testing
+
+## Test Performance
+
+Tests are performed at various levels of frequency.
+
+### Per-merge Testing
+
+Before changes are merged, the author of the changes must perform:
+
+* _Smoke testing_ (both generally, and for areas which interact with
+  the new changes.)
+* _Unit testing_ (as part of the automated build step.)
+
+Changes are not merged until the author has affirmed that both
+forms of testing have been performed successfully; this is documented
+by the [Author Checklist](https://github.com/nasa/openmctweb/blob/master/CONTRIBUTING.md#author-checklist).
+
+### Per-sprint Testing
+
+### Per-release Testing