Improve new syntax files and fix a region glitch

runtime/syntax/dot.yaml

@@ -1,16 +1,27 @@
 filetype: dot
 
-detect: 
+detect:
     filename: "\\.(dot|gv)$"
 
 rules:
-    - type: "\\b(digraph|edge|graph|node|subgraph)\\b"
+    - type:   "\\b(digraph|edge|graph|node|subgraph)\\b"
     - statement: "\\b(arrow(head|size|tail)|(bg|fill|font)?color|center|constraint|decorateP|dir|distortion|font(name|size)|head(clip|label)|height|label(angle|distance|font(color|name|size))?|layer(s)?|margin|mclimit|minlen|name|nodesep|nslimit|ordering|orientation|page(dir)?|peripheries|port_label_distance|rank(dir|sep)?|ratio|regular|rotate|same(head|tail)|shape(file)?|sides|size|skew|style|tail(clip|label)|URL|weight|width)\\b"
-    - symbol: "=|->|--"
-    - constant.string: "\"(\\\\.|[^\"])*\"|'(\\\\.|[^'])*'"
-    - comment: "(^|[[:space:]])//.*"
+    - symbol:  "=|->|--"
+
+    - constant.string:
+        start: "\""
+        end: "\""
+        rules:
+            - constant.specialChar: "\\\\."
+
+    - comment:
+        start: "//"
+        end: "$"
+        rules:
+            - todo: "(TODO|XXX|FIXME):?"
+
     - comment:
         start: "/\\*"
         end: "\\*/"
-        rules: []
-
+        rules:
+            - todo: "(TODO|XXX|FIXME):?"