Add sgtpooki to lotus-docs

[BigLep]

Needed in support of filecoin-project/filecoin-pin#49

This can be removed in a couple of weeks.

[BigLep]

@rjan90 : I'll plan on merging this to unblock @SgtPooki. Just created this though so there is visibility and record of the change.

[github-actions]

The following access changes will be introduced as a result of applying the plan:

Access Changes

User sgtpooki:
  - will gain push permission to lotus-docs

[github-actions]

Before merge, verify that all the following plans are correct. They will be applied as-is after the merge.

Terraform plans

filecoin-project

Terraform used the selected providers to generate the following execution
plan. Resource actions are indicated with the following symbols:
  + create

Terraform will perform the following actions:

  # github_repository_collaborator.this["lotus-docs:sgtpooki"] will be created
  + resource "github_repository_collaborator" "this" {
      + id                          = (known after apply)
      + invitation_id               = (known after apply)
      + permission                  = "push"
      + permission_diff_suppression = false
      + repository                  = "lotus-docs"
      + username                    = "SgtPooki"
    }

Plan: 1 to add, 0 to change, 0 to destroy.