runtime(doc): update and correct str2blob() and blob2str() examples

closes: #16952

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

Author: h-east

runtime/doc/builtin.txt

@@ -1,4 +1,4 @@
-*builtin.txt*	For Vim version 9.1.  Last change: 2025 Mar 18
+*builtin.txt*	For Vim version 9.1.  Last change: 2025 Mar 22
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -1323,9 +1323,11 @@ blob2str({blob} [, {options}])				*blob2str()*
 		See also |str2blob()|
 
 		Examples: >
-			blob2str(0z6162)	returns ["ab"]
-			blob2str(0zC2ABC2BB)	returns ["«»"]
-			blob2str(0zABBB, {'encoding': 'latin1'}) returns ["«»"]
+		    blob2str(0z6162)		returns ['ab']
+		    blob2str(0zC2ABC2BB)	returns ['«»']
+		    blob2str(0z610A62)		returns ['a', 'b']
+		    blob2str(0z610062)		returns ['a\nb']
+		    blob2str(0zABBB, {'encoding': 'latin1'}) returns ['«»']
 <
 		Can also be used as a |method|: >
 			GetBlob()->blob2str()
@@ -10666,11 +10668,12 @@ str2blob({list} [, {options}])					*str2blob()*
 		See also |blob2str()|
 
 		Examples: >
-		    str2blob(["ab"])	returns 0z6162
-		    str2blob(["«»"])	returns 0zC2ABC2BB
-		    str2blob(["a\nb"])	returns 0z610A62
-		    str2blob(readfile('myfile.txt'))
+		    str2blob(["ab"])		returns 0z6162
+		    str2blob(["«»"])		returns 0zC2ABC2BB
+		    str2blob(["a\nb"])		returns 0z610062
+		    str2blob(["a","b"])		returns 0z610A62
 		    str2blob(["«»"], {'encoding': 'latin1'}) returns 0zABBB
+		    str2blob(readfile('myfile.txt'))
 <
 		Can also be used as a |method|: >
 			GetListOfStrings()->str2blob()