Make editing footer & navbar links easier

Pull links from resource files

_data/english-department-links.yml

@@ -0,0 +1,3 @@
+- title: Twitter
+  url: https://twitter.com/RSEnglishDept
+  icon: twitter

_data/navigation-links.yml

@@ -0,0 +1,4 @@
+- title: Reading School Website
+  url: https://reading-school.co.uk
+- title: Home
+  url: /

_data/school-links.yml

@@ -0,0 +1,12 @@
+- title: Twitter
+  url: https://twitter.com/readingsch
+  icon: twitter
+- title: Instagram
+  url: https://instagram.com/reading_sch
+  icon: instagram
+- title: Facebook
+  url: https://facebook.com/ReadingSchoolOfficial
+  icon: facebook
+- title: LinkedIn
+  url: https://linkedin.com/school/reading-school
+  icon: linkedin