Remove deprecated installation guide reference

Removed deprecated installation guide from documentation. Since georchestra/georchestra#4557

Author: f-necas

documentation.md

@@ -13,7 +13,6 @@ permalink: /documentation.html
 ## geOrchestra main documentation
 
 <div class="row py-2 d-flex align-items-stretch">
-    {% include card_doc_tool.html img_url="/favicon.ico" name="Installation guide" text="Only installation guide (to be deprecated before summer 2025)" site_url="https://github.com/georchestra/georchestra/blob/master/docsv1/index.md" %}
     {% include card_doc_tool.html img_url="/favicon.ico" name="Installation and administration guide" text="All new documentation, work in progress" site_url="https://docs.georchestra.org/georchestra/" %}
     <br />
     {% include card_doc_tool.html img_url="/favicon.ico" name="Gateway" text="The Gateway, the central entry point for all geOrchestra services" site_url="https://docs.georchestra.org/gateway/" %}
@@ -49,4 +48,4 @@ permalink: /documentation.html
     {% include card_doc_tool.html img_url="/public/icons/ldapadmin_icon.svg" name="Console" text="An administration console for users, roles and organisations" site_url="https://github.com/georchestra/georchestra/tree/master/console" %}
     {% include card_doc_tool.html img_url="/public/icons/analytics_icon.svg" name="Analytics" text="A module presenting statistics on use of the platform" site_url="https://docs.georchestra.org/analytics/" %}  
     {% include card_doc_tool.html img_url="/public/icons/ldapadmin_icon.svg" name="Mviewer Studio" text="An mviewer application generator" site_url="https://mviewerstudio.readthedocs.io/fr/stable/index.html" %}   
-</div>
+</div>