[GIT-45] fix: allow markdown file attachments (#8524)

* fix: allow markdown file attachments

- Add text/markdown to ATTACHMENT_MIME_TYPES
- Fixes issue where .md files were rejected with 'Invalid file type' error

* added the support for frontend mime type too

apps/api/plane/settings/common.py

@@ -380,6 +380,7 @@ ATTACHMENT_MIME_TYPES = [
     "application/vnd.ms-powerpoint",
     "application/vnd.openxmlformats-officedocument.presentationml.presentation",
     "text/plain",
+    "text/markdown",
     "application/rtf",
     "application/vnd.oasis.opendocument.spreadsheet",
     "application/vnd.oasis.opendocument.text",

packages/editor/src/core/constants/config.ts

@@ -26,6 +26,7 @@ export const ACCEPTED_ATTACHMENT_MIME_TYPES = [
   "application/vnd.ms-powerpoint",
   "application/vnd.openxmlformats-officedocument.presentationml.presentation",
   "text/plain",
+  "text/markdown",
   "application/rtf",
   "audio/mpeg",
   "audio/wav",