.gitignore: add some more commonly used files

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

.gitignore

@@ -1,9 +1,12 @@
 dist/
+node_modules/
 /host
 *.o
 *.so
 *.swp
 *.po~
+*.mo
+package-lock.json
 modules/luci-base/src/po2lmo
 modules/luci-base/src/jsmin
 modules/luci-base/src/contrib/lemon