Template for starting a new resource grammar (#441)

Also addressing this https://github.com/GrammaticalFramework/gf-rgl/issues/238 with a README that adds a suggested implementation order.

src/TEMPLATE/GrammarTMP.gf

@@ -0,0 +1,17 @@
+concrete GrammarTMP of Grammar =
+    NounTMP
+  , VerbTMP
+  , AdjectiveTMP
+  , AdverbTMP
+  , NumeralTMP
+  , SentenceTMP
+  , QuestionTMP
+  , RelativeTMP
+  , ConjunctionTMP
+  , PhraseTMP
+  , TextX
+  , StructuralTMP
+  , IdiomTMP
+  , TenseX
+  , NamesTMP -- Not part of original Grammar, here to trigger compilation
+  ;