Switch to pipx instead of pip in README.

README.md

@@ -57,11 +57,11 @@ total: 946 words
 
 ## Installation
 
-Start by cloning the project with git. Then install it with Python's `pip`.
-Example:
+Start by cloning the project with git. Then install it with
+[pipx](https://pypa.github.io/pipx/). Example:
 
 ```bash
-pip3 install /path/to/novel-stats
+pipx install /path/to/novel-stats
 ```
 
 ## Usage
@@ -226,7 +226,7 @@ make sure your changes work.
 
 ```bash
 cd novel-stats/
-pip3 install --editable --user .
+pipx install --editable .
 ```
 
 Note that this will typically install the novel-stats commands into
@@ -245,7 +245,7 @@ you're in the `novel-stats/` working copy, install tox, which is used for
 setting up testing environments:
 
 ```bash
-pip3 install --user tox
+pipx install tox
 ```
 
 Finally, to actually run tests, run: