Node.gitignore: correct term for instrumentation

Node.gitignore

@@ -18,7 +18,7 @@ results
 
 # Code coverage patterns
 
-## Directory for coverage-hooked libs generated by jscoverage/JSCover
+## Directory for instrumented libs generated by jscoverage/JSCover
 lib-cov
 
 ## Coverage directory used by tools like istanbul