Fixed typo in docs. (#1818)

docs/faq_debug.md

@@ -92,7 +92,7 @@ First you have to compile frimware with this build option `NKRO_ENABLE` in **Mak
 
 Try `Magic` **N** command(`LShift+RShift+N` by default) when **NKRO** still doesn't work. You can use this command to toggle between **NKRO** and **6KRO** mode temporarily. In some situations **NKRO** doesn't work you need to switch to **6KRO** mode, in particular when you are in BIOS.
 
-If your firmeare built with `BOOTMAGIC_ENABLE` you need to turn its switch on by `BootMagic` **N** command(`Space+N` by default). This setting is stored in EEPROM and keeped over power cycles.
+If your firmware built with `BOOTMAGIC_ENABLE` you need to turn its switch on by `BootMagic` **N** command(`Space+N` by default). This setting is stored in EEPROM and keeped over power cycles.
 
 https://github.com/tmk/tmk_keyboard#boot-magic-configuration---virtual-dip-switch