[docs] substitute upgradation with upgrade

docs/docs/.vitepress/sidebar.ts

@@ -279,8 +279,8 @@ export const sidebar = [
                         link: "/self-hosting/installation/post-install/",
                     },
                     {
-                        text: "Upgradation",
-                        link: "/self-hosting/installation/upgradation",
+                        text: "Upgrade",
+                        link: "/self-hosting/installation/upgrade",
                     }
 
                 ],

docs/docs/self-hosting/installation/post-install/index.md

@@ -145,6 +145,6 @@ You can download Ente CLI from [here](https://github.com/ente-io/ente/releases?q
 
 Check our [documentation](/self-hosting/administration/cli) on how to use Ente CLI for managing self-hosted instances.
 
-::: info For upgradation
-Check out our [upgradation documentation](/self-hosting/installation/upgradation) for various installation methods.
+::: info For upgrading
+Check out our [upgrading documentation](/self-hosting/installation/upgrade) for various installation methods.
 :::

docs/docs/self-hosting/installation/upgrade.md

@@ -1,6 +1,6 @@
 ---
 title: Upgrade - Self-hosting
-description: Upgradation of self-hosted Ente
+description: Upgrading self-hosted Ente
 ---
 
 # Upgrade your server