docs: add PagerDuty-specific information

Author: wilsonehusin

docs/opsgenie.md

@@ -0,0 +1,18 @@
+# PagerDuty to Signals
+
+We support importing from PagerDuty to Signals. To get started, please set up the following environment variables:
+
+```shell
+export FIREHYDRANT_API_KEY=your-firehydrant-api-key
+export PROVIDER=PagerDuty
+export PROVIDER_API_KEY=your-pagerduty-api-key
+```
+
+> [!NOTE]
+> Read-only key for PagerDuty should be sufficient.
+
+Afterwards, run `signals-migrator import` and follow the prompts.
+
+## Known limitations
+
+- While we support importing "PagerDuty Service" as "FireHydrant Team", we still require the Teams API to be accessible. If your account does not have access to the Teams API, please see [#27](https://github.com/firehydrant/signals-migrator/issues/27) and let us know what error you encountered.

docs/pagerduty.md

@@ -2,13 +2,6 @@
 
 This can be used to import resources from legacy alerting providers into Signals.
 
-## Supported providers
-
-### Alerting 
-
-- PagerDuty
-- VictorOps
-- OpsGenie
 
 ## Usage
 
@@ -42,19 +35,18 @@ On the other hand, we can't reliably match teams ourselves as they have wide var
 
 Afterwards, the tool will generate the mapping appropriately, handling de-duplication and merging as necessary.
 
-## Feature roadmap
+## Supported providers
+
+We support importing from various providers. Refer to individual documentation for provider-specific instructions:
 
 | | PagerDuty | Opsgenie | VictorOps |
 | --- | --- | --- | --- |
+| Docs | [PagerDuty](./docs/pagerduty.md) | [Opsgenie](./docs/opsgenie.md) | [VictorOps](./docs/victorops.md) |
 | Import users | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | Import teams and members | :white_check_mark: | :white_check_mark: | :white_check_mark: |
 | Import escalation policies | :white_check_mark: | :white_check_mark: | :x: |
 | Import scheduling strategy | :white_check_mark: | :white_check_mark: | :x: |
 
-
-- [ ] Getting transposer URLs (e.g. Datadog) to the team data resource or a Signals ingest URL data resource
-- [ ] Auto-run `terraform apply` for users who would not manage their organization with Terraform after importing
-
 ## Developing
 
 A devcontainer setup has been prepared to be used in VS Code. Run `direnv allow` to auto-load `.env` file.