Fix a link: remove extra # in href value (#3276)

Author: AlexanderLukin

public/docs/ts/latest/guide/testing.jade

@@ -1855,7 +1855,7 @@ table
     td
       :marked
         The testing shims (`karma-test-shim`, `browser-test-shim`) 
-        establish the [initial test environment](##testbed-initTestEnvironment) and a default testing module.
+        establish the [initial test environment](#testbed-initTestEnvironment) and a default testing module.
         The default testing module is configured with basic declaratives and some Angular service substitutes that every tester needs.
 
         Call `configureTestingModule` to refine the testing module configuration for a particular set of tests