Tweaks to the analysis server benchmarks.

pkg/analysis_server/benchmark/readme.md

 # Analysis Server Benchmarks
 
 ## How to run the benchmarks
 
 To see a list of all available benchmarks, run:
 
 ```
-dart benchmarks/benchmarks.dart list
+dart benchmark/benchmarks.dart list
 ```
 
 To run an individual benchmark, run:
 
 ```
-dart benchmarks/benchmarks.dart run <benchmark-id>
+dart benchmark/benchmarks.dart run <benchmark-id>
 ```
 
 ## How they're tested
 
 In order to make sure that our benchmarks don't regress in terms of their
 ability to run, we create one unit test per benchmark, and run those tests
 as part of our normal CI test suite.
 
 To save time on the CI, we only run one iteration of each benchmark
 (`--repeat=1`), and we run the benchmark on a smaller data set (`--quick`).
 
 See `test/benchmark_test.dart`.
 
 ## To add a new benchmark
 
-Register the new benchmark in then main() method of benchmarks/benchmarks.dart.
+Register the new benchmark in the `main()` method of benchmark/benchmarks.dart.
 
 ## On the bots
 
-Our benchmarks run on a continuous performance testing system. It will run
-any benchmark produced by the `benchmarks/benchmarks.dart list` command.
-
-To not run a benchmark on the bot, define the benchmark with the `disable` flag.
+Our benchmarks run on a continuous performance testing system. Currently, the
+benchmarks need to be manually registered ahead of time.