Add docs for homeassistant.tag_scanned action (#763)

* Add docs for homeassistant.tag_scanned

* Add pn532 example

* Add example to rdm6300

components/api.rst

@@ -208,6 +208,26 @@ Configuration options:
 - **variables** (*Optional*, mapping): Optional variables that can be used in the ``data_template``.
   Values are :ref:`lambdas <config-lambda>` and will be evaluated before sending the request.
 
+
+.. _api-homeassistant_tag_scanned_action:
+
+``homeassistant.tag_scanned`` Action
+------------------------------------
+
+When using the native API with Home Assistant, you can push tag_scanned to Home Assistant
+straight from ESPHome :ref:`Automations <automation>`.
+
+.. code-block:: yaml
+
+    # In some trigger
+    on_...:
+      # Simple
+      - homeassistant.tag_scanned: some-tag
+
+Configuration options:
+
+- **tag** (**Required**, :ref:`templatable <config-templatable>`, string): The id of the scanned tag
+
 See Also
 --------
 

components/binary_sensor/pn532.rst

@@ -86,6 +86,17 @@ The parameter ``x`` this trigger provides is of type ``std::string`` and is the
               topic: pn532/tag
               payload: !lambda 'return x;'
 
+A tag scanned event can also be sent to the Home Assistant tag component
+using :ref:`api-homeassistant_tag_scanned_action`.
+
+.. code-block:: yaml
+
+    pn532:
+      # ...
+      on_tag:
+        then:
+          - homeassistant.tag_scanned: !lambda 'return x;'
+
 .. _pn532-tag:
 
 NFC/RFID Tag

components/binary_sensor/rdm6300.rst

@@ -70,6 +70,17 @@ unsigned integer.
               topic: rdm6300/tag
               payload: !lambda 'return uint32_to_string(x);'
 
+A tag scanned event can also be sent to the Home Assistant tag component
+using :ref:`api-homeassistant_tag_scanned_action`.
+
+.. code-block:: yaml
+
+    rdm6300:
+      # ...
+      on_tag:
+        then:
+          - homeassistant.tag_scanned: !lambda 'return uint32_to_string(x);'
+
 .. _rdm6300-tag:
 
 NFC/RFID Tag