Use pipx for install

README.md

@@ -36,26 +36,16 @@ Instructions
 Install *pandoc-numbering* using the bash command
 
 ~~~shell
-$ pip install pandoc-numbering
+$ pipx install pandoc-numbering
 ~~~
 
 To upgrade to the most recent release, use
 
 ~~~shell
-$ pip install --upgrade pandoc-numbering
+$ pipx install --upgrade pandoc-numbering
 ~~~
 
-To upgrade to the current code, use
-
-~~~shell
-$ pip install --upgrade --force --no-cache git+https://github.com/chdemko/pandoc-numbering
-~~~
-
-`pip` is a script that downloads and installs modules from the Python Package Index, [PyPI].  It should come installed with your python distribution. If you are running linux, `pip` may be bundled separately. On a Debian-based system (including Ubuntu), you can install it as root using
-
-~~~shell
-$ sudo apt-get install python3-pip
-~~~
+`pipx` is a script to install and run python applications in isolated environments from the Python Package Index, [PyPI]. It can be installed using instructions given [here](https://pipx.pypa.io/stable/).
 
 Make sure you have the