Replace ">=" by "≥" in README

Author: flashcode

README.adoc

@@ -17,7 +17,7 @@ image:https://github.com/flashcode/msgcheck/workflows/Tests/badge.svg["Tests", l
 
 The script requires:
 
-* Python >= 2.7
+* Python ≥ 2.7
 * gettext (for the command `msgfmt`, used to compile PO files)
 * the python module `pyenchant` if spelling is checked (with option `-s`).