add deps doc page

README.md

@@ -115,15 +115,14 @@ openupm view com.my.package
 Checkout [the commands doc page](./docs/cmd-view.md) for more information.
 
 ### View package dependencies
-```
-openupm deps <pkg>
-```
 
-Using option `--deep` to view dependencies recursively
+Use `openupm deps` to print package dependencies.
 
+```sh
+openupm deps com.my.package
 ```
-openupm deps <pkg> --deep
-```
+
+Checkout [the commands doc page](./docs/cmd-deps.md) for more information.
 
 ### Authenticate with a scoped registry
 

docs/cmd-deps.md

@@ -0,0 +1,44 @@
+# `openupm deps`
+
+The `deps` command prints the names and versions of dependencies for a package.
+
+The command will first search openupm and then the Unity registry to find the package.
+
+This command has the `dep` alias. On this doc page we will always use the primary command name `deps`.
+
+## Arguments
+
+### Package reference
+
+The name of the package for which you want to resolve dependencies. The general format for a package reference is `name@version`. 
+
+```sh
+openupm deps com.my.package@1.0.0
+```
+
+The version may be a specific version or predefined tag. The `deps` command does not work for url versions. For more information about how the version can be specified checkout the corresponding [help page](./help-package-reference.md).
+
+
+## Options
+
+### Deep
+
+By default the `deps` command will only resolve and print a packages direct dependencies. If you want to recursively print all dependencies (ie the full dependency tree) you can run with the `--deep` option.
+
+```sh
+openupm deps com.my.package --deep
+```
+
+### Registry
+
+By default openupm finds packages on the openupm and Unity registries in that order. This behavior is configurable, specifically if you want to work with 3rd party registries. 
+
+You can override the primary registry from which to resolve packages using the  `--registry` option.
+
+```sh
+openupm deps com.my.package --registry https://packages.my.registry
+```
+
+### Windows system-user authentication
+
+This command supports Windows system-user authentication. For more information check out the corresponding [article](./help-system-user.md).