feat: add DecapCMS configuration and update admin redirects

public/_redirects

@@ -4,4 +4,5 @@
 /#invite_token=* /auth?invite_token=:splat 200
 
 # Admin panel redirect
-/admin/* /decapcms/index.html 200
+/admin/ /decapcms/index.html 200
+/admin/index.html /decapcms/index.html 200

public/admin/config.yml

@@ -0,0 +1,65 @@
+backend:
+  name: git-gateway
+  branch: main
+  accept_roles:
+    - admin
+    - editor
+  squash_merges: true
+
+media_folder: 'src/assets/images'
+public_folder: '~/assets/images'
+
+locale: 'tr'
+
+site_url: https://taslak.radio.org.tr
+display_url: https://taslak.radio.org.tr
+
+collections:
+  - name: 'post'
+    label: 'Blog Yazıları'
+    folder: 'src/data/post'
+    create: true
+    slug: '{{year}}-{{month}}-{{day}}-{{slug}}'
+    fields:
+      - label: 'Başlık'
+        name: 'title'
+        widget: 'string'
+      - label: 'Yayın Tarihi'
+        name: 'date'
+        widget: 'datetime'
+        format: 'YYYY-MM-DD HH:mm:ss'
+      - label: 'Yazar'
+        name: 'author'
+        widget: 'string'
+        default: 'TA1SPH'
+      - label: 'Kategoriler'
+        name: 'categories'
+        widget: 'list'
+        allow_add: true
+        allow_delete: true
+        collapsed: false
+        field:
+          label: 'Kategori'
+          name: 'category'
+          widget: 'string'
+      - label: 'Etiketler'
+        name: 'tags'
+        widget: 'list'
+        allow_add: true
+        allow_delete: true
+        collapsed: false
+        field:
+          label: 'Etiket'
+          name: 'tag'
+          widget: 'string'
+      - label: 'Düzen'
+        name: 'layout'
+        widget: 'string'
+        default: 'post'
+      - label: 'Öne Çıkan Görsel'
+        name: 'image'
+        widget: 'image'
+        required: false
+      - label: 'İçerik'
+        name: 'body'
+        widget: 'markdown'