Move docs/ to docs/en/

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docs/en/adns9800.md

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+# ADNS9800
+Add this module for controlling ADNS9800 optical sensor.
+```python
+from kmk.modules.adns9800 import ADNS9800
+keyboard.modules.append(ADNS9800(cs=board.GP0, sclk=board.GP2, miso=board.GP4, mosi=board.GP3, invert_y=True))
+```
+
+Firmware for this sensor has to be obtained separately and placed in `kmk\modules\adns9800_firmware.py`
+```python
+firmware = (
+    b'\x03'
+    b'\xa6'
+    ...
+)
+```
+
+## Constructor parameters
+
+ADNS9800(cs=*cs_pin*, sclk=*clock_pin*, miso=*miso_pin*, mosi=*mosi_pin*, invert_x=*False*, invert_y=*False*)