docs: fix typo

Author: isti115

src/flockwave/server/ext/virtual_uavs/battery.py

@@ -41,7 +41,7 @@ def __init__(
                 charge with some small variation.
             report_percentage: whether the virtual battery reports its charge
                 percentage as well as its voltage
-            auto_rechargin: whether the virtual battery automatically
+            auto_recharging: whether the virtual battery automatically
                 recharges itself when its voltage drops below the minimum
                 voltage
         """