(#279) - use lowercase for all documentation files

Consistency makes linking between pages easier.

Author: ccarouge

…ocs/pages/infrastructure/Architecture.md …ocs/pages/infrastructure/architecture.mddocumentation/docs/pages/infrastructure/Architecture.md renamed to documentation/docs/pages/infrastructure/architecture.md documentation/docs/pages/infrastructure/Architecture.md renamed to documentation/docs/pages/infrastructure/architecture.md

@@ -38,10 +38,10 @@ nav:
         - Sea Ice: pages/diagnostics/sea_ice.md #do not edit directly, change 
           # sea_ice_source.ipynb then export as HTML and rename that file to sea_ice.md
   - Infrastructure:    
-        - Architecture:          pages/infrastructure/Architecture.md
-        - Deployment:            pages/infrastructure/Deployment.md
-        - Building:              pages/infrastructure/Building.md
-        - Git practices:         pages/infrastructure/Git-practices.md
+        - Architecture:          pages/infrastructure/architecture.md
+        - Deployment:            pages/infrastructure/deployment.md
+        - Building:              pages/infrastructure/building.md
+        - Git practices:         pages/infrastructure/git-practices.md
 
 # Theme
 theme: