doc: Refine README.links further

suggested by Chapman Flack 

diff --git a/doc/src/sgml/README.links b/doc/src/sgml/README.links
index 388fdc6ee64e0dfbfd788e8831187ee393896c41..db6577d243691b7b55ddd78ce22dc54a451ef77a 100644 (file)
--- a/doc/src/sgml/README.links
+++ b/doc/src/sgml/README.links
@@ -40,6 +40,10 @@ url=
 Guidelines
 ----------
 
-o  If you want to supply text, use , else 
-o  Specific nouns like GUC variables, SQL commands, and contrib modules
-   usually have xreflabels
+- For an internal link, if you want to supply text, use , else
+  .
+
+- Specific nouns like GUC variables, SQL commands, and contrib modules
+  usually have xreflabels.
+
+- For an external link, use , with or without link text.