Update portainer install docs (#9421)

* Update portainer.md

* Update portainer.md

* chore: cleanup

---------

Co-authored-by: Jason Rasmussen <jrasm91@gmail.com>

docs/docs/install/portainer.md

@@ -38,8 +38,9 @@ style={{border: '1px solid #ddd'}}
 alt="Dot Env Example"
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-- Populate custom database information if necessary.
-- Populate `UPLOAD_LOCATION` with your preferred location for storing backup assets.
+- Change the default `DB_PASSWORD`, and add custom database connection information if necessary.
+- Change `DB_DATA_LOCATION` to a folder where the database will be saved to disk.
+- Change `UPLOAD_LOCATION` to a folder where media (uploaded and generated) will be stored.
 
 11. Click on "**Deploy the stack**".