Rename keyboards with uppercase letters (#18268)

keyboards/converter/numeric_keypad_iie/numeric_keypad_iie.c

@@ -13,4 +13,4 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include "numeric_keypad_IIe.h"
+#include "numeric_keypad_iie.h"

keyboards/converter/numeric_keypad_iie/readme.md

@@ -11,6 +11,6 @@ Hardware Supported: Internal Numeric Keypad IIe PCB (Apple part 820.0081.c), ATm
 
 Make example for this keyboard (after setting up your build environment):
 
-    make converter/numeric_keypad_IIe:default
+    make converter/numeric_keypad_iie:default
 
 See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).