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
This rule specifies that the policy will be applied to all requests that match the following criteria: 
 
 - The p_type is 'p' (policy) 
 - The v0 value is 'admin' 
 - The v1 value is a path prefix that will match '/:company/:project/:team' 
 - The v2 value is a path prefix that will match '/companies/public-domains' 
 - The v3 value is 'POST'