Mention how to remake eterm-color (moved here from ../Makefile).

etc/e/README

@@ -2,7 +2,10 @@ eterm-color.ti is a terminfo source file.  eterm-color is a compiled
 version produced by the terminfo compiler (tic).  The compiled files
 are binary, and depend on the version of tic, but they seem to be
 system-independent and backwardly compatible.  So there should be no
-need to recompile (see etc/Makefile) the distributed binary version.
+need to recompile the distributed binary version.  If it is
+necessary, use:
+
+tic -o ../ ./eterm-color.ti
 
 The compiled file is used by lisp/term.el, so if it is moved term.el
 needs to be changed.  terminfo requires it to be stored in an `e'