clean-up

reorganize the wiki using only two-levels of directories

project/contribute.md

@@ -22,3 +22,7 @@ At the moment, there are few ways to contribute:
 
 > You can have a look at [the ongoing issues](https://kanboard.phyllo.me/b/CH7qd98J2v7egmodk/development) to get an indication on what to do next.
 {.is-info}
+
+---
+
+*[**Go to parent page**](https://wiki.phyllo.me/)*

project/infrastructure.md

@@ -120,4 +120,8 @@ Apps that were actively disabled post-installation:
 
 * **Description** : [Wiki.js](https://js.wiki/) is used to power the wiki 
 * **Location** : https://wiki.phyllo.me
-* **Maintainer** : lukas@phyllo.me
+* **Maintainer** : lukas@phyllo.me
+
+---
+
+*[**Go to parent page**](https://wiki.phyllo.me/)*

project/join.md

@@ -34,4 +34,8 @@ To receive an invitation, you need to possess an email address. Then, you should
 Please note that all contributions made to the project, through the official tools stated below, will be open-sourced.
  
 > As a contributor, you waive your rights to profit from Phyllome OS. You will be added to the list of contributors.
-{.is-warning}
+{.is-warning}
+
+---
+
+*[**Go to parent page**](https://wiki.phyllo.me/)*