Add community section

#148

Author: MattiSG

content/api/_index.md

@@ -1,4 +1,4 @@
 ---
 title: API
-weight: 6
+weight: 4
 ---

content/collections/_index.md

@@ -1,4 +1,4 @@
 ---
 title: Collections
-weight: 5
+weight: 3
 ---

content/community/_index.md

@@ -0,0 +1,4 @@
+---
+title: "Community"
+weight: 7
+---

content/community/how-to-join-mattermost.md

@@ -0,0 +1,5 @@
+---
+title: How to join Mattermost
+---
+
+# How to join Mattermost

content/design-principles.en.md

@@ -1,6 +1,5 @@
 ---
 title: "Design principles"
-weight: 10
 ---
 
 # Design principles

content/guidelines/_index.md

@@ -1,4 +1,4 @@
 ---
 title: "Guidelines"
-weight: 8
+weight: 5
 ---

content/memos/_index.md

@@ -0,0 +1,4 @@
+---
+title: "Memos"
+weight: 6
+---