patch 9.1.0778: filetype: lf config files are not recognized

Problem:  filetype: lf config files are not recognized
Solution: detect lfrc files as lf filetype, include a syntax
          script for lf files (Andis Spriņķis).

References:
- https://github.com/gokcehan/lf

closes: #15859

Signed-off-by: Andis Spriņķis <spr.andis@protonmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 53af240..221b32e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    778,
+/**/
     777,
 /**/
     776,