patch 8.2.3917: the eval.txt help file is way too big

Problem:    The eval.txt help file is way too big.
Solution:   Move the builtin function details to a separate file.
diff --git a/runtime/doc/remote.txt b/runtime/doc/remote.txt
index c6dcb98..02b675a 100644
--- a/runtime/doc/remote.txt
+++ b/runtime/doc/remote.txt
@@ -143,7 +143,7 @@
 FUNCTIONS
 								*E240* *E573*
 There are a number of Vim functions for scripting the command server.  See
-the description in |eval.txt| or use CTRL-] on the function name to jump to
+the description in |builtin.txt| or use CTRL-] on the function name to jump to
 the full explanation.
 
     synopsis				     explanation ~