We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Add overlay tiles layers from settings
https://github.com/makinacorpus/django-leaflet/issues/83 

Would allow to show cadastral parcels over orthophoto, "plans de circulation" etc.


--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `geotrek/settings/dev.py`
Content:
```
1 from .default import *  # NOQA
2 
3 #
4 # Django Development
5 # ..........................
6 
7 DEBUG = True
8 TEMPLATE_DEBUG = True
9 
10 SOUTH_TESTS_MIGRATE = False  # Tested at settings.tests
11 
12 #
13 # Developper Toolbar
14 # ..........................
15 
16 INSTALLED_APPS = (
17     # 'debug_toolbar',
18     'django_extensions',
19 ) + INSTALLED_APPS
20 
21 #
22 # Use Geotrek preprod tiles (uses default extent)
23 # ................................................
24 
25 LEAFLET_CONFIG['TILES'] = [
26     (gettext_noop('Scan'), 'http://{s}.tile.osm.org/{z}/{x}/{y}.png', '(c) OpenStreetMap Contributors'),
27     (gettext_noop('Ortho'), 'http://{s}.tiles.mapbox.com/v3/openstreetmap.map-4wvf9l0l/{z}/{x}/{y}.jpg', '(c) MapBox'),
28 ]
29 LEAFLET_CONFIG['SRID'] = 3857
30 
31 LOGGING['loggers']['geotrek']['level'] = 'DEBUG'
32 LOGGING['loggers']['']['level'] = 'DEBUG'
33
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/geotrek/settings/dev.py b/geotrek/settings/dev.py
--- a/geotrek/settings/dev.py
+++ b/geotrek/settings/dev.py
@@ -19,13 +19,17 @@
 ) + INSTALLED_APPS
 
 #
-# Use Geotrek preprod tiles (uses default extent)
-# ................................................
+# Use some default tiles
+# ..........................
 
 LEAFLET_CONFIG['TILES'] = [
     (gettext_noop('Scan'), 'http://{s}.tile.osm.org/{z}/{x}/{y}.png', '(c) OpenStreetMap Contributors'),
     (gettext_noop('Ortho'), 'http://{s}.tiles.mapbox.com/v3/openstreetmap.map-4wvf9l0l/{z}/{x}/{y}.jpg', '(c) MapBox'),
 ]
+LEAFLET_CONFIG['OVERLAYS'] = [
+    (gettext_noop('Coeur de parc'), 'http://{s}.tilestream.makina-corpus.net/v2/coeur-ecrins/{z}/{x}/{y}.png', 'Ecrins'),
+]
+
 LEAFLET_CONFIG['SRID'] = 3857
 
 LOGGING['loggers']['geotrek']['level'] = 'DEBUG'

{"golden_diff": "diff --git a/geotrek/settings/dev.py b/geotrek/settings/dev.py\n--- a/geotrek/settings/dev.py\n+++ b/geotrek/settings/dev.py\n@@ -19,13 +19,17 @@\n ) + INSTALLED_APPS\n \n #\n-# Use Geotrek preprod tiles (uses default extent)\n-# ................................................\n+# Use some default tiles\n+# ..........................\n \n LEAFLET_CONFIG['TILES'] = [\n     (gettext_noop('Scan'), 'http://{s}.tile.osm.org/{z}/{x}/{y}.png', '(c) OpenStreetMap Contributors'),\n     (gettext_noop('Ortho'), 'http://{s}.tiles.mapbox.com/v3/openstreetmap.map-4wvf9l0l/{z}/{x}/{y}.jpg', '(c) MapBox'),\n ]\n+LEAFLET_CONFIG['OVERLAYS'] = [\n+    (gettext_noop('Coeur de parc'), 'http://{s}.tilestream.makina-corpus.net/v2/coeur-ecrins/{z}/{x}/{y}.png', 'Ecrins'),\n+]\n+\n LEAFLET_CONFIG['SRID'] = 3857\n \n LOGGING['loggers']['geotrek']['level'] = 'DEBUG'\n", "issue": "Add overlay tiles layers from settings\nhttps://github.com/makinacorpus/django-leaflet/issues/83 \n\nWould allow to show cadastral parcels over orthophoto, \"plans de circulation\" etc.\n\n", "before_files": [{"content": "from .default import *  # NOQA\n\n#\n# Django Development\n# ..........................\n\nDEBUG = True\nTEMPLATE_DEBUG = True\n\nSOUTH_TESTS_MIGRATE = False  # Tested at settings.tests\n\n#\n# Developper Toolbar\n# ..........................\n\nINSTALLED_APPS = (\n    # 'debug_toolbar',\n    'django_extensions',\n) + INSTALLED_APPS\n\n#\n# Use Geotrek preprod tiles (uses default extent)\n# ................................................\n\nLEAFLET_CONFIG['TILES'] = [\n    (gettext_noop('Scan'), 'http://{s}.tile.osm.org/{z}/{x}/{y}.png', '(c) OpenStreetMap Contributors'),\n    (gettext_noop('Ortho'), 'http://{s}.tiles.mapbox.com/v3/openstreetmap.map-4wvf9l0l/{z}/{x}/{y}.jpg', '(c) MapBox'),\n]\nLEAFLET_CONFIG['SRID'] = 3857\n\nLOGGING['loggers']['geotrek']['level'] = 'DEBUG'\nLOGGING['loggers']['']['level'] = 'DEBUG'\n", "path": "geotrek/settings/dev.py"}], "after_files": [{"content": "from .default import *  # NOQA\n\n#\n# Django Development\n# ..........................\n\nDEBUG = True\nTEMPLATE_DEBUG = True\n\nSOUTH_TESTS_MIGRATE = False  # Tested at settings.tests\n\n#\n# Developper Toolbar\n# ..........................\n\nINSTALLED_APPS = (\n    # 'debug_toolbar',\n    'django_extensions',\n) + INSTALLED_APPS\n\n#\n# Use some default tiles\n# ..........................\n\nLEAFLET_CONFIG['TILES'] = [\n    (gettext_noop('Scan'), 'http://{s}.tile.osm.org/{z}/{x}/{y}.png', '(c) OpenStreetMap Contributors'),\n    (gettext_noop('Ortho'), 'http://{s}.tiles.mapbox.com/v3/openstreetmap.map-4wvf9l0l/{z}/{x}/{y}.jpg', '(c) MapBox'),\n]\nLEAFLET_CONFIG['OVERLAYS'] = [\n    (gettext_noop('Coeur de parc'), 'http://{s}.tilestream.makina-corpus.net/v2/coeur-ecrins/{z}/{x}/{y}.png', 'Ecrins'),\n]\n\nLEAFLET_CONFIG['SRID'] = 3857\n\nLOGGING['loggers']['geotrek']['level'] = 'DEBUG'\nLOGGING['loggers']['']['level'] = 'DEBUG'\n", "path": "geotrek/settings/dev.py"}]}