Restored Troubleshooting.md and associated files

docs/docs/behavior/key-press.md

@@ -27,6 +27,11 @@ There is an [open issue](https://github.com/zmkfirmware/zmk/issues/21) to provid
 complete set of defines for the full keypad and consumer usage pages in the future for ZMK.
 :::
 
+### Improperly defined keymap - `dtlib.DTError: <board>.dts.pre.tmp:<line number>`
+
+When compiling firmware from a keymap, it may be common to encounter an error in the form of a`dtlib.DTError: <board>.dts.pre.tmp:<line number>`.
+For instructions to resolve such an error, click [here](../troubleshooting###Improperly-defined-keymap)
+
 ## Keypad Key Press
 
 The "keypad key press" behavior sends standard keypad keycodes on press/release.

docs/docs/troubleshooting.md

@@ -0,0 +1,33 @@
+---
+id: troubleshooting
+title: Troubleshooting
+sidebar_title: Troubleshooting
+---
+### Summary
+
+The following page provides suggestions for common errors that may occur during firmware compilation. If the information provided is insufficient to resolve the issue, feel free to seek out help from the [ZMK Discord](https://zmkfirmware.dev/community/discord/invite).
+
+### Environment Variables not Defined
+
+An error along the lines of `CMake Error at (zmk directory)/zephyr/cmake/generic_toolchain.cmake:64 (include): include could not find load file:` during firmware compilation indicates that the Zephyr Environment Variables are not properly defined.
+For more information, click [here](../docs/dev-setup#environment-variables).
+
+### Improperly defined keymap
+
+An error along the lines of `dtlib.DTError: <board>.dts.pre.tmp:<line number>` during firmware compilation indicates an issue within the `<shield>.keymap` file.
+This can be verified by checking the file in question, found in `mkdir/app/build`.
+
+|       ![Example Error Screen](../docs/assets/troubleshooting/keymaps/errorscreen.png)                                             |
+| :-------------------------------------------------------------------------------:                                                 |
+|            An example of the dtlib.DTError when compiling an iris with the nice!nano while the keymap is not properly defined     |
+
+After opening the `<board>.dts.pre.tmp:<line number>` and scrolling down to the referenced line, one can locate errors within their shield's keymap by checking if the referenced keycodes were properly converted into the correct [USB HID Usage ID](https://www.usb.org/document-library/hid-usage-tables-12).
+
+|       ![Unhealthy Keymap Temp](../docs/assets/troubleshooting/keymaps/unhealthyEDIT.png)  |
+| :-------------------------------------------------------------------------------: |
+| An incorrectly defined keymap unable to compile. As shown in red, `&kp SPAC` is not a valid 
+reference to the [USB HID Usage ID](https://www.usb.org/document-library/hid-usage-tables-12) used for "Keyboard Spacebar"       |
+
+|  ![Healthy Keymap Temp](../docs/assets/troubleshooting/keymaps/healthyEDIT.png)  |
+| :-------------------------------------------------------------------------------: |
+|  A properly defined keymap with successful compilation. As shown in red, the corrected keycode (`&kp SPC`) references the proper Usage ID defined in the [USB HID Usage Tables](https://www.usb.org/document-library/hid-usage-tables-12)|