patch 8.1.1218: cannot set a directory for a tab page
Problem: Cannot set a directory for a tab page.
Solution: Add the tab-local directory. (Yegappan Lakshmanan, closes #4212)
diff --git a/runtime/doc/index.txt b/runtime/doc/index.txt
index 83be4a5..c95de5b 100644
--- a/runtime/doc/index.txt
+++ b/runtime/doc/index.txt
@@ -1623,6 +1623,8 @@
|:tab| :tab create new tab when opening new window
|:tag| :ta[g] jump to tag
|:tags| :tags show the contents of the tag stack
+|:tcd| :tcd change directory for tab page
+|:tchdir| :tch[dir] change directory for tab page
|:tcl| :tc[l] execute Tcl command
|:tcldo| :tcld[o] execute Tcl command for each line
|:tclfile| :tclf[ile] execute Tcl script file