feat(backend): support epd_waveshare (#127)

* feat: support epd_waveshare

* docs: add epd-waveshare instructions

* fix: formatting

Co-authored-by: Jagoda Estera Ślązak <128227338+j-g00da@users.noreply.github.com>

* docs: add epd-waveshare example

* chore: cleanup

* chore: update deps

* chore: clean up the implementation

* style: fix formatting

* chore: build the EPD waveshare demo in CI

* chore: set up esp toolchain for EPD waveshare example

* chore: remove empty loop

* fix: remove Ok(()) from main

* chore: allow empty loop

---------

Co-authored-by: Jagoda Estera Ślązak <128227338+j-g00da@users.noreply.github.com>
Co-authored-by: Orhun Parmaksız <orhunparmaksiz@gmail.com>

Author: 3 people

.github/workflows/ci.yml

@@ -70,6 +70,11 @@ jobs:
             dir: examples/mousefood-esp32-std-demo
             target: xtensa-esp32-espidf
             setup_xtensa: true
+          # EPD Waveshare demo 
+          - name: epd-waveshare-demo
+            dir: examples/epd-waveshare-demo
+            target: ""
+            setup_xtensa: true
     steps:
       - name: Checkout
         uses: actions/checkout@v6