Update coverage.md

Removed unneeded reference to `make with_coverage`.

Author: dwRchyngqxs

docs/coverage.md

@@ -1,7 +1,7 @@
 Coverage information
 ====================
 
-If you want to know which part of your code is executed when running your compiler on a file you can build your compiler with `make with_coverage`, run your compiler on the file, then run `make coverage`.
+If you want to know which part of your code is executed when running your compiler on a file you can run your compiler on the file, then run `make coverage`.
 
 This will generate a webpage `coverage/index.html` with a listing of all the source files and for each source file a listing of the number of times each line has been executed.