docs: Add AgentQL provider doc, tool/toolkit doc and documentloader doc (#30144)

- **Description:** Added AgentQL docs for the provider page, tools page
and documentloader page
- **Twitter handle:** @AgentQL

Repo:
https://github.com/tinyfish-io/agentql-integrations/tree/main/langchain
PyPI: https://pypi.org/project/langchain-agentql/

If no one reviews your PR within a few days, please @-mention one of
baskaryan, eyurtsev, ccurme, vbarda, hwchase17.

---------

Co-authored-by: Chester Curme <chester.curme@gmail.com>

docs/scripts/tool_feat_table.py

@@ -147,6 +147,11 @@ WEBBROWSING_TOOL_FEAT_TABLE = {
         "interactions": True,
         "pricing": "40 free requests/day",
     },
+    "AgentQL Toolkit": {
+        "link": "/docs/integrations/tools/agentql",
+        "interactions": True,
+        "pricing": "Free trial, with pay-as-you-go and flat rate plans after",
+    },
 }
 
 DATABASE_TOOL_FEAT_TABLE = {