fix: Use bundler over bundle (#2500)

* Have gem install bundler and use it to do the installs.

Author: matthewfeickert

Diff for: pages/docs/webdev.md

@@ -37,7 +37,7 @@ rbenv local 3.1.2
 This will run the Ruby you just built whenever you enter this directory. You'll want to install bundler too:
 
 ```bash
-gem install bundle
+gem install bundler
 ```
 
 (You may want to add `--user-install` here if you are not using rbenv. And if

Diff for: pixi.toml

@@ -9,7 +9,7 @@ platforms = ["linux-64", "osx-64", "osx-arm64", "win-64"]
 [tasks]
 # Need to use '--user-install' as using pixi instead of rbenv
 install = """
-gem install --user-install bundle && \
+gem install --user-install bundler && \
 bundle install
 """