Add tests documentation.

README.md

@@ -1,3 +1,13 @@
 # acid
 
 Tests to identify faults and incorrect behavior in the Redox microkernel.
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+### Tests
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+- `acid switch` - test to see the context switch time (500/500 for P/C acronyms).
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+P - Parent context switch count (500 by deafult)
+C - Child context switch count (500 by deafult)
+T - Timestamp counter difference
+
+(timestamp counter is not reliable on every system).