Explain to me this casbin rule {
 p\_type: 'p',
 v0: 'admin',
 v1: '/:company/:project/:team',
 v2: '/companies/public-domains',
 v3: 'POST',
 },
 This is a rule for the Casbin authorization library. Casbin is a powerful and efficient open-source access control library. It uses policies to make access control decisions. A policy is a set of rules that define who can access what resources under what conditions.

The rule you provided has the following components:

* `p_type: 'p'`: This indicates that the rule is a policy rule. Casbin uses two types of rules: policy rules (p) and role rules (g). Policy rules define the policy for a specific object and action, while role rules define the hierarchy of roles.
* `v0: 'admin'`: This indicates the subject or role that the rule applies to. In this case, the rule applies to the 'admin' role.
* `v1: '/:company/:project/:team'`: This indicates the object or resource that the rule applies to. In this case, the rule applies to any resource that matches the URL pattern '/:company/:project/:team'. The colons indicate that these are variables that can be replaced with specific values.
* `v2: '/companies/public-domains'`: This indicates an additional object or resource that the rule applies to. In this case, the rule also applies to the resource '/companies/public-domains'.
* `v3: 'POST'`: This indicates the action or operation
A Casbin rule!

Let's break it down:

**p_type: 'p'**: This specifies the policy type, which in this case is a "p" policy, short for "policy". This is the most common type of policy in Casbin.

**v0: 'admin'**: This is the first value in the policy rule, which represents the role or user that this rule applies to. In this case, it's an "admin" user.

**v1: '/:company/:project/:team'**: This is the second value in the policy rule, which represents the resource that the rule applies to. The colon (`:`) is a placeholder for a parameter, so this resource path has three parameters:

* `:company`
* `:project`
* `:team`

This means that the rule applies to any resource path that matches this pattern, such as `/acme/incubator/team-a` or `/example/project-x/team-y`.

**v2: '/companies/public-domains'**: This is the third value in the policy rule, which represents another resource that the rule applies to. This resource path is a literal string, not a parameterized path like `v1`.

**v3: 'POST'**: This is the fourth value in the policy rule, which represents the HTTP method that the rule applies to. In this case, it's the `POST` method.

So, when we put it all together, this Casbin rule