patch 8.2.0156: various typos in source files and tests

Problem:    Various typos in source files and tests.
Solution:   Fix the typos. (Emir Sari, closes #5532)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index c0ed1c8..6df6975 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -6134,7 +6134,7 @@
 }
 
 /*
- * ":edit <file>" command and alikes.
+ * ":edit <file>" command and alike.
  */
     void
 do_exedit(