feat: added flask docs

Author: slaveeks

docs/flask.md

@@ -0,0 +1,92 @@
+# Flask integration
+
+This extension adds support for the [Flask](http://flask.pocoo.org/) web framework.
+
+## Installation
+
+```bash
+pip install hawkcatcher[flask]
+```
+
+import Catcher module to your project.
+
+```python
+from hawkcatcher.modules.flask import HawkFlask
+```
+
+```python
+hawk = HawkFlask(
+    "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJwcm9qZWN0SWQiOiI1ZTZmNWM3NzAzOWI0MDAwMjNmZDViODAiLCJpYXQiOjE1ODQzNTY0NzF9.t-5Gelx3MgHVBrxTsoMyPQAdQ6ufVbPsts9zZLW3gM8")
+```
+
+Now all global flask errors would be sent to Hawk.
+
+### Try-except
+
+If you want to catch errors in try-except blocks see [this](../README.md#try-except)
+
+## Manual sending
+
+You can send any error to Hawk. See [this](../README.md#manual-sending)
+
+### Event context
+
+See [this](../README.md#event-context)
+
+### Affected user
+
+See [this](../README.md#affected-user)
+
+### Addons
+
+When some event handled by Flask Catcher, it adds some addons to the event data for Hawk.
+
+| name      | type | description       |
+| --------- | ---- | ----------------- |
+| `url`     | str  | Request URL       |
+| `method`  | str  | Request method    |
+| `headers` | dict | Request headers   |
+| `cookies` | dict | Request cookies   |
+| `params`  | dict | Request params    |
+| `form`    | dict | Request form      |
+| `json`    | dict | Request json data |
+
+## Init params
+
+To init Hawk Catcher just pass a project token.
+
+```python
+hawk = HawkFlask('1234567-abcd-8901-efgh-123456789012')
+```
+
+### Additional params
+
+If you need to use custom Hawk server then pass a dictionary with params.
+
+```python
+hawk = HawkFlask({
+    'token': '1234567-abcd-8901-efgh-123456789012',
+    'collector_endpoint': 'https://<id>.k1.hawk.so',
+})
+```
+
+Parameters:
+
+| name                 | type                      | required     | description                                                                  |
+| -------------------- | ------------------------- | ------------ | ---------------------------------------------------------------------------- |
+| `token`              | str                       | **required** | Your project's Integration Token                                             |
+| `release`            | str                       | optional     | Release name for Suspected Commits feature                                   |
+| `collector_endpoint` | string                    | optional     | Collector endpoint for sending event to                                      |
+| `context`            | dict                      | optional     | Additional context to be send with every event                               |
+| `before_send`        | Callable[[dict], None]    | optional     | This Method allows you to filter any data you don't want sending to Hawk     |
+| `set_user`           | Callable[[Request], User] | optional     | This Method allows you to set user for every request by flask request object |
+| `with_addons`        | bool                      | optional     | Add framework addons to event data                                           |
+
+## Requirements
+
+See [this](../README.md#requirements)
+
+And for flask you need:
+
+- Flask
+- blinker