docs: update PR template with current guidelines

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,10 +1,29 @@
 <!---
-    For keyboard addition or changes, Vial will accept keyboards that implement "default" and "via" keymaps.
-    For Vial-enabled keymaps please ensure that VIAL_INSECURE is not set.
 
-    User keymaps (i.e. https://github.com/vial-kb/vial-qmk/tree/vial/users) will not be accepted at the moment.
+    If you are submitting a Vial-enabled keymap for a keyboard in QMK:
 
-    For other core changes, please explain what you are changing and why.
+    - Keymaps will not be accepted with VIAL_INSECURE=yes.
+    - Avoid changing keyboard-level code if possible (ex: switching the encoder pins in info.json)
+    - Please name your keymap "vial". Personal keymaps are not accepted at this time.
+      - If your Vial keymap only works for a specific keyboard revision, place it under that specific revision's folder. Ex: keyboards/planck/rev6_drop/keymaps/vial and keyboards/planck/ez/glow/keymaps/vial
+
+    If you are submitting a new keyboard with keymaps:
+
+    - If you are also submitting this keyboard to QMK, please try to submit mostly the same code to both places if possible.
+    - If you are not submitting this keyboard to QMK, only include "default" and "vial" keymaps. VIA firmware can no longer be built by this repository.
+
+    ------
+
+    For all keyboard and keymap submissions:
+
+    As the submitter, you are ultimately responsible for maintaining the keyboards/keymaps you submit.
+    Vial maintainers will try to fix compilation issues as updates are made, but are not always familiar with and often have no way to test specific keymaps/keyboards.
+
+    Vial is decentralized, so inclusion in the vial-qmk repository is optional. Any keymaps/keyboards in this repository which break and cannot be fixed without extensive rework and/or strong familiarity with the hardware may be removed, with or without warning.
+
+    ------
+
+    For core changes, please explain what you are changing and why.
 
     Before submitting a PR, delete the entirety of this comment and document your changes.
 -->