docs: per-resource examples, service subcategories, and auth/migration guides

- examples/: a self-contained, terraform-fmt-clean Terraform example for every
  resource (25) and data source (19), plus import.sh for importable resources.
  tfplugindocs renders these as the "Example Usage" and "Import" sections.
- templates/resources.md.tmpl + data-sources.md.tmpl: derive a per-service
  "subcategory" from the type name so the registry groups pages by Identity,
  Images, Networking, Compute, and Block Storage.
- templates/guides/: an Authentication guide (password/token/app-cred, clouds.yaml,
  TLS, endpoint overrides, precedence) and a Migrating-from-terraform-provider-
  openstack guide (name mapping, behavioral notes, import workflow).
- gitignore docs/guides/ (rendered like the rest of docs/, produced by make generate).

Verified: terraform fmt -check on ./examples passes, make generate renders all
pages with Example Usage/Import + guides, build/gofmt clean.

Author: PF9-pushkar

.gitignore

@@ -33,9 +33,11 @@ PCD-CE-Deployment-Handoff.md
 
 # Generated registry docs — produced by `make generate` (tfplugindocs) on demand and
 # at release time; not committed. (docs/compatibility/ is hand-written and kept.)
+# Guides are authored in templates/guides/ and rendered into docs/guides/.
 /docs/index.md
 /docs/resources/
 /docs/data-sources/
+/docs/guides/
 
 # Editors / OS
 .idea/

CHANGELOG.md

@@ -0,0 +1,3 @@
+data "pcd_blockstorage_snapshot" "example" {
+  name = "tf-example-snapshot"
+}

examples/data-sources/pcd_blockstorage_snapshot/data-source.tf

@@ -0,0 +1,3 @@
+data "pcd_blockstorage_volume" "example" {
+  name = "tf-example-volume"
+}

examples/data-sources/pcd_blockstorage_volume/data-source.tf

@@ -0,0 +1,3 @@
+data "pcd_compute_availability_zones" "example" {
+  state = "available"
+}

examples/data-sources/pcd_compute_availability_zones/data-source.tf

@@ -0,0 +1,3 @@
+data "pcd_compute_flavor" "example" {
+  name = "m1.large"
+}

examples/data-sources/pcd_compute_flavor/data-source.tf

@@ -0,0 +1,3 @@
+data "pcd_compute_keypair" "example" {
+  name = "tf-example-keypair"
+}

examples/data-sources/pcd_compute_keypair/data-source.tf

@@ -0,0 +1,4 @@
+data "pcd_identity_auth_scope" "example" {
+  name   = "tf-example-scope"
+  region = "RegionOne"
+}

examples/data-sources/pcd_identity_auth_scope/data-source.tf

@@ -0,0 +1,3 @@
+data "pcd_identity_project" "example" {
+  name = "tf-example-project"
+}

examples/data-sources/pcd_identity_project/data-source.tf

@@ -0,0 +1,3 @@
+data "pcd_identity_role" "example" {
+  name = "member"
+}