patch 8.1.0757: not enough documentation for Blobs

Problem:    Not enough documentation for Blobs.
Solution:   Add a section about Blobs.
diff --git a/src/version.c b/src/version.c
index 6317a8e..d96ec6e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -796,6 +796,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    757,
+/**/
     756,
 /**/
     755,