docs: make SQLite environment example runnable

.env.example

@@ -16,7 +16,9 @@ LOG_LEVEL='info'
 
 # This is how you can use the sqlite driver:
 DB_DRIVER='better-sqlite3'
-DB_URL='FULL_PATH_TO_YOUR_SQLITE_DB_FILE'
+# Safe local source-development path. SQLite files are ignored by Git.
+# Container images use /appdata/db/db.sqlite by default instead.
+DB_URL='./db.sqlite'
 
 # Those are the two ways to use the mysql2 driver:
 # 1. Using the URL format:

apps/docs/docs/getting-started/installation/source.mdx

@@ -38,8 +38,9 @@ This method is only useful, when you want to develop on Homarr or extend it with
     Install all dependencies using <code>pnpm install</code>
   </li>
   <li>
-    Copy the `.env.example` file to `.env` and replace `DB_URL` with the full path you want to use for the sqlite
-    database file. For example `DB_URL='/home/username/homarr/db.sqlite`
+    Copy the `.env.example` file to `.env`. Its `DB_URL='./db.sqlite'` value is ready for local use and stores the
+    database in the cloned repository. Replace it with an absolute writable path such as
+    `DB_URL='/home/username/homarr/db.sqlite'` if you want to store the database elsewhere.
   </li>
   <li>
     Replace `AUTH_SECRET` and `SECRET_ENCRYPTION_KEY` both with a secure random string by using `openssl rand -hex 32`