docs: add v2 and v3 installation and usage guide

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: “saileshwar-skyflow”

docs/v2-v3-installation.md

@@ -0,0 +1,78 @@
+# Skyflow Python SDK — v2 (PDB) and v3 (FlowDB) Installation
+
+## v2 — PDB SDK
+
+### Install
+
+```bash
+pip install "skyflow-python==2.0.0"
+```
+
+### Initialize client
+
+```python
+from skyflow import SkyflowClient, SkyflowConfig, Credentials
+
+client = SkyflowClient(
+    SkyflowConfig(
+        vault_id="<VAULT_ID>",
+        cluster_id="<CLUSTER_ID>",
+        credentials=Credentials(api_key="<API_KEY>"),
+    )
+)
+```
+
+### Insert
+
+```python
+from skyflow import InsertRequest
+
+response = client.vault().insert(
+    InsertRequest(
+        table="cards",
+        values=[{"card_number": "4111111111111111", "cardholder_name": "John Doe"}],
+        return_tokens=True,
+    )
+)
+print(response)
+# {"records": [{"skyflow_id": "...", "table": "cards"}], "errors": []}
+```
+
+---
+
+## v3 — FlowDB SDK
+
+### Install
+
+```bash
+pip install "skyflow-python==3.0.0"
+```
+
+### Initialize client
+
+```python
+from skyflow import SkyflowClient, SkyflowConfig, Credentials
+
+client = SkyflowClient(
+    SkyflowConfig(
+        vault_id="<VAULT_ID>",
+        cluster_id="<CLUSTER_ID>",
+        credentials=Credentials(api_key="<API_KEY>"),
+    )
+)
+```
+
+### Insert
+
+```python
+from skyflow import InsertRequest
+
+response = client.vault().insert(
+    InsertRequest(
+        table="records",
+        values=[{"field_name": "value"}],
+    )
+)
+print(response)
+# {"records": [{"skyflow_id": "...", "table": "records"}], "errors": []}
+```