Add 'always hide CC drawer' option

When the CC starts up, it opens the drawer by default. The option
introduced by this commit closes it as soon as the content script gets
injected into the page.

Feature suggested at pekb/thread/67965396?msgid=69642485

Fixes: #10
Change-Id: I2a043dc9888eee2c9b1f98713d36cd1a49d3c931
diff --git a/src/_locales/ca/messages.json b/src/_locales/ca/messages.json
index 911bb44..6a77a77 100644
--- a/src/_locales/ca/messages.json
+++ b/src/_locales/ca/messages.json
@@ -75,6 +75,10 @@
     "message": "la configuració del mode fosc del SO",
     "description": "Select option added in #ccdarktheme_mode--container, in the options_ccdarktheme string"
   },
+  "options_ccforcehidedrawer": {
+    "message": "Amaga sempre la barra lateral de l'esquerra a la Consola de la Comunitat.",
+    "description": "Feature checkbox in the options page"
+  },
   "options_profileindicator_header": {
     "message": "Punt indicador",
     "description": "Heading for the profile indicator feature options"