chore(obsidian): Update Obsidian attachment config and tidy assets

Clear markdownUrlFormat in plugin config to restore default URL
behavior and prevent incorrect generated attachment paths.

Remove obsolete generated images and add the current screenshot
asset. Update workspace.json to reflect asset changes and insert
a reference to the new image in docs/obsidian.md.

Signed-off-by: alanhc <alan.tseng.cs@gmail.com>

Author: alanhc

docs/.obsidian/plugins/obsidian-custom-attachment-location/data.json

@@ -13,7 +13,7 @@
   "generatedAttachmentFileName": "file-${date:YYYYMMDDHHmmssSSS}",
   "includePaths": [],
   "jpegQuality": 0.8,
-  "markdownUrlFormat": "assets/${noteFileName}/${geneatedAttachmentFileName}",
+  "markdownUrlFormat": "",
   "renamedAttachmentFileName": "",
   "shouldConvertPastedImagesToJpeg": false,
   "shouldDeleteOrphanAttachments": false,

docs/.obsidian/workspace.json

@@ -186,6 +186,9 @@
   },
   "active": "e8e61b022fb722ce",
   "lastOpenFiles": [
+    "assets/obsidian/file-20251206225649111.png",
+    "assets/obsidian",
+    "assets/obsidian/file-20251206225633195.png",
     "assets/obsidian/file-20251206225446317.png",
     "assets/obsidian/file-20251206225439106.png",
     "assets/obsidian/file-20251206225250654.png",
@@ -197,9 +200,6 @@
     "assets/obsidian/file-20251206225145146.png",
     "assets/obsidian/file-20251206225017624.png",
     "assets/obsidian/file-20251206224957087.png",
-    "assets/obsidian",
-    "assets/截圖 2025-11-05 晚上7.24.58.png",
-    "assets/截圖 2025-11-05 晚上7.24.21.png",
     "android.md",
     "簡報.md",
     "反直覺.md",