patch 8.2.3703: most people call F# "fsharp" and not "fs"

Problem:    Most people call F# "fsharp" and not "fs".
Solution:   Rename filetype "fs" to "fsharp".
diff --git a/src/version.c b/src/version.c
index 302db8e..a190af5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3703,
+/**/
     3702,
 /**/
     3701,