patch 8.2.2435: setline() gives an error for some types

Problem:    setline() gives an error for some types.
Solution:   Allow any type, convert each item to a string.

runtime/doc/eval.txt

@@ -1,4 +1,4 @@
-*eval.txt*	For Vim version 8.2.  Last change: 2021 Jan 22
+*eval.txt*	For Vim version 8.2.  Last change: 2021 Jan 31
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -293,13 +293,13 @@ is not available it returns zero or the default value you specify: >
 
 
 List concatenation ~
-
+							*list-concatenation*
 Two lists can be concatenated with the "+" operator: >
 	:let longlist = mylist + [5, 6]
 	:let mylist += [7, 8]
 
-To prepend or append an item turn the item into a list by putting [] around
-it.  To change a list in-place see |list-modification| below.
+To prepend or append an item, turn the item into a list by putting [] around
+it.  To change a list in-place, refer to |list-modification| below.
 
 
 Sublist ~
@@ -3133,6 +3133,7 @@ append({lnum}, {text})					*append()*
 		text line below line {lnum} in the current buffer.
 		Otherwise append {text} as one text line below line {lnum} in
 		the current buffer.
+		Any type of item is accepted and converted to a String.
 		{lnum} can be zero to insert a line before the first one.
 		Returns 1 for failure ({lnum} out of range or out of memory),
 		0 for success.  Example: >
@@ -9409,6 +9410,8 @@ setline({lnum}, {text})					*setline()*
 		{lnum} is used like with |getline()|.
 		When {lnum} is just below the last line the {text} will be
 		added below the last line.
+		{text} can be any type or a List of any type, each item is
+		converted to a String.
 
 		If this succeeds, FALSE is returned.  If this fails (most likely
 		because {lnum} is invalid) TRUE is returned.