Add documentation for GCP cloud storage destination

Adds documentation for the GCP cloud storage data destination.

Signed-off-by: Daniel Mangum <georgedanielmangum@gmail.com>

Author: hasheddan

docs/data-routing/4-destinations/12-gcp-cloud-storage.md

@@ -0,0 +1,92 @@
+---
+title: gcp-cloud-storage
+---
+
+|   |   |
+|---|:---:|
+|__Latest Version__| `v1.0.0` |
+|__Input Content Type__| Any |
+
+:::usage
+Sending data to GCP Cloud Storage incurs usage costs after exceeding the free
+tier. See [Golioth pricing](https://golioth.io/pricing) for more information.
+:::
+
+The `gcp-cloud-storage` destination sends data to a [Google Cloud Platform Cloud
+Storage](https://cloud.google.com/cloud-storage) bucket.
+
+### Parameters
+
+|Parameter|Type|Description|Required|
+|---|---|---|:---:|
+|`service_account`|`string`| The GCP Service Account key used for authentication. |✅|
+|`name`|`string`| The name of the GCP Cloud Storage bucket. |✅|
+
+### Example Secrets
+
+`GCP_SERVICE_ACCOUNT`
+```
+{
+  "type": "service_account",
+  "project_id": "my-gcp-project",
+  "private_key_id": "87984ikjddkpda896fa8932jk2",
+  "private_key": "-----BEGIN RSA PRIVATE KEY-----.....",
+  "client_email": "test-account@my-gcp-project.iam.gserviceaccount.com",
+  "client_id": "75091285748954182",
+  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
+  "token_uri": "https://oauth2.googleapis.com/token",
+  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
+  "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/test-account%40my-gcp-projec.iam.gserviceaccount.com"
+}
+```
+
+### Example Usage
+
+```yaml
+    destination:
+      type: gcp-cloud-storage
+      version: v1
+      parameters:
+        service_account: $GCP_SERVICE_ACCOUNT
+        name: my-bucket
+```
+
+### Example Input
+
+> Binary data displayed as hex encoded for documentation purposes only.
+
+```
+00000000: 5249 4646 ffff ffff 5741 5645 666d 7420  RIFF....WAVEfmt
+00000010: 1000 0000 0100 0100 c05d 0000 80bb 0000  .........]......
+00000020: 0200 1000 6461 7461 ffff ffff eaff edff  ....data........
+00000030: f0ff f5ff f9ff feff 0100 0300 0800 0b00  ................
+00000040: 0b00 0c00 0a00 0800 0500 0100 fbff f8ff  ................
+```
+
+### Example Output
+
+Input data is uploaded to the Google Cloud Storage bucket as an
+[object](https://cloud.google.com/storage/docs/objects) with content unmodified.
+
+> Binary data displayed as hex encoded for documentation purposes only.
+
+```
+00000000: 5249 4646 ffff ffff 5741 5645 666d 7420  RIFF....WAVEfmt
+00000010: 1000 0000 0100 0100 c05d 0000 80bb 0000  .........]......
+00000020: 0200 1000 6461 7461 ffff ffff eaff edff  ....data........
+00000030: f0ff f5ff f9ff feff 0100 0300 0800 0b00  ................
+00000040: 0b00 0c00 0a00 0800 0500 0100 fbff f8ff  ................
+```
+
+Objects are created with name matching the event ID in a directory with
+name matching the device ID. An example directory structure is shown below.
+
+```
+/
+├─ 664b9e889a9590ccfcf822b3/
+│  ├─ 28ebd981-80ae-467f-b700-ba00e7c1e3ee
+│  ├─ e47e5b46-d4e3-4bf1-a413-9fc71ec9f6b0
+│  ├─ ...
+├─ 66632a45658c93af0895a70e/
+├─ .../
+```