README.md: Update the documentation

Refer to modifiers with their new names, and to Kaleidoscope as such (as opposed
to KaleidoscopeFirmware, a remnant of KeyboardioFirmware, I suppose).

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>

README.md

@@ -50,16 +50,16 @@ There are two macros the plugin provides:
 
 ### `OSM(mod)`
 
-> A macro that takes a single argument, the name of the modifier: `LCtrl`,
+> A macro that takes a single argument, the name of the modifier: `LeftCtrl`,
-> `LShift`, `LAlt`, `LGUI` or their right-side variant. When marked up with this
+> `LeftShift`, `LeftAlt`, `LeftGUI` or their right-side variant. When marked up
-> macro, the modifier will act as a one-shot modifier.
+> with this macro, the modifier will act as a one-shot modifier.
 
 ### `OSL(layer)`
 
 > Takes a layer number as argument, and sets up the key to act as a one-shot
 > layer key.
 >
-> Please note that while `KaleidoscopeFirmware` supports more, one-shot layers are
+> Please note that while `Kaleidoscope` supports more, one-shot layers are
 > limited to 24 layers only.
 
 ## Plugin methods