update readme (#101)

README.md

@@ -31,6 +31,7 @@ Table of contents
   * [Update dependencies -- for package consumers](#update-dependencies----for-package-consumers)
   * [Use gyro in Github Actions](#use-gyro-in-github-actions)
     * [Publishing from an action](#publishing-from-an-action)
+  * [Completion Scripts](#completion-scripts)
 * [Design philosophy](#design-philosophy)
 * [Generated files](#generated-files)
   * [gyro.zzz](#gyrozzz)
@@ -256,38 +257,30 @@ gyro remove iguanaTLS --from some_package
 
 ### Local development
 
-Right now local development requires editing [gyro.zzz](#gyrozzz), there will be a cli
-workflow in a future release.
+One can switch out a dependency for a local copy using the `redirect`
+subcommand. Let's say we're using `mattnite/tar` from astrolabe and we come
+across a bug, we can debug with a local version of the package by running:
 
-Let's say you have a dependency, `iguanaTLS`, and you have it cloned next to
-your project. Your gyro.zzz will look something like this:
-
-```yaml
-deps:
-  alexnask/iguanaTLS: ^0.0.1
+```
+gyro redirect -a tar -p ../tar
 ```
 
-You can comment out the package and replace it with a local one:
+This will point gyro at your local copy, and when you're done you can revert the
+redirect(s) with:
 
-```yaml
-deps:
-  #alexnask/iguanaTLS: ^0.0.1
-  iguanaTLS: src: local: "../iguanaTLS"
+```
+gyro redirect --clean
 ```
 
-If the package had more than one exported package then you'd need to specify the
-root file:
+Multiple dependencies can be redirected. Build dependencies are redirected by
+passing `-b`. You can even redirect the dependencies of a local package.
 
-```yaml
-deps:
-  #alexnask/iguanaTLS: ^0.0.1
-  iguanaTLS:
-    root: src/blarg.zig
-    src: local: "../iguanaTLS"
-```
+HOT tip: add this to your git `pre-commit` hook to catch you before accidentally
+commiting redirects:
 
-It is possible to go down the dependency tree further by doing this to the
-`gyro.zzz` file in the local dependency.
+```
+gyro redirect --check
+```
 
 ### Update dependencies -- for package consumers
 
@@ -336,6 +329,19 @@ jobs:
           GYRO_ACCESS_TOKEN: ${{ secrets.GYRO_ACCESS_TOKEN }}
 ```
 
+### Completion Scripts
+
+Completion scripts can be generated by the `completion` subcommand, it is run
+like so:
+
+```
+gyro completion -s <shell> <install path>
+```
+
+Right now only `zsh` is the only supported shell, and this will create a `_gyro`
+file in the install path. If you are using `oh-my-zsh` then this path should be
+`$HOME/.oh-my-zsh/completions`.
+
 ## Design philosophy
 
 The two main obectives for gyro are providing a great user experience and