Merge from origin/emacs-28

9dadcbe429 ; * doc/misc/eshell.texi (Dollars Expansion): Fix markup.
2c3d1b6bf4 Improve/correct documentation about Eshell variable expansion
9e257aecc9 Partially revert b03f74e0f2a578b1580e8b1c368665850ee7f808

diff --cc doc/misc/eshell.texi
Simple merge

diff --cc lisp/eshell/esh-var.el
Simple merge

diff --cc test/lisp/eshell/eshell-tests.el
Simple merge