tools: update .gitignore file

This makes sure we do not ignore eslint files that should actually
be updated. We need to explicitly whitelist the folder and the files.
Otherwise peer dependencies might not be updated as expected.

.gitignore

@@ -2,7 +2,6 @@
 .*
 !deps/**/.*
 !test/fixtures/**/.*
-!tools/node_modules/**/.*
 !tools/doc/node_modules/**/.*
 !.clang-format
 !.editorconfig
@@ -19,6 +18,12 @@
 !.eslintrc.yaml
 !.cpplint
 
+./node_modules
+
+# Whitelist all dependencies related to eslint
+!tools/node_modules
+!tools/node_modules/**/*
+
 core
 vgcore.*
 v8*.log
@@ -76,7 +81,6 @@ deps/icu
 deps/icu*.zip
 deps/icu*.tgz
 deps/icu-tmp
-./node_modules
 android-toolchain/
 
 # generated by gyp on Windows