Sort remaining keywords

See the previous commit for an explanation

data/keywords.txt

@@ -1,39 +1,39 @@
-if
-elif
-else
-for
-do
-while
-match
-switch
-case
+assert
 break
-continue
-pass
-return
+breakpoint
+case
 class
 class_name
-extends
-is
-self
-tool
-signal
-func
-static
 const
+continue
+do
+elif
+else
 enum
-var
-onready
 export
-setget
-breakpoint
-preload
-yield
-assert
-remote
-master
-slave
-sync
-in
-true
+extends
 false
+for
+func
+if
+in
+is
+master
+match
+onready
+pass
+preload
+remote
+return
+self
+setget
+signal
+slave
+static
+switch
+sync
+tool
+true
+var
+while
+yield