Provided custom meta descriptions for each page and post

Signed-off-by: Jim Martens <github@2martens.de>

_includes/head.html

@@ -4,7 +4,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
     <title>{% if page.title %}{{ page.title }} - {% endif %}{{ site.title }}</title>
     <meta name="description"
-          content="{% if page.excerpt %}{{ page.excerpt | strip_html | strip_newlines | truncate: 160 }}{% else %}{{ site.description }}{% endif %}">
+          content="{% if post.excerpt %}{{ post.excerpt | strip_html | strip_newlines | truncate: 160 }}{% elif page.description %}{{ page.description }}{% else %}{{ site.description }}{% endif %}">
 
     {% asset main.css %}
     {% asset fa-svg-with-js.css %}

blog/index.html

@@ -2,6 +2,7 @@
 layout: category
 title: Blog
 category: blog
+description: On this page you can find all my blog posts that don't fit somewhere else.
 ---
 
 <h1>Blog</h1>

cs/index.html

@@ -2,6 +2,7 @@
 layout: category
 title: Computer Science
 category: cs
+description: This page gives an overview over my university activities, including but not limited to publications.
 ---
 
 <h1>Computer Science</h1>

pages/404.html

@@ -1,6 +1,7 @@
 ---
 title: 404 - Link not found
 permalink: /404.html
+description: The link you have tried to access, doesn't exist.
 ---
 
 <div class="container my-3">

pages/cv.html

@@ -2,6 +2,7 @@
 title: Curriculum Vitae
 permalink: /cv/
 sidebarboxes: cv-pdf job_offers encrypted-communication
+description: On this page you can find my curriculum vitae.
 ---
 
 {% if site.data.author.image %}

pages/datenschutzerklärung.html

@@ -1,6 +1,7 @@
 ---
 title: Datenschutzerklärung
 permalink: /datenschutz/
+description: Die Datenschutzerklärung für diese Website kann hier gefunden werden.
 ---
 
 For your convenience there is an <a href="{{ site.baseurl }}{% link pages/privacy-policy.html %}">English version</a> available.

pages/impressum.html

@@ -1,6 +1,7 @@
 ---
 title: Impressum
 permalink: /impressum/
+description: Das Impressum für diese Website kann hier gefunden werden.
 ---
 
 For your convenience there is an <a href="{{ site.baseurl }}{% link pages/legal-notice.html %}">English version</a> available.

pages/legal-notice.html

@@ -1,6 +1,7 @@
 ---
 title: Legal Notice
 permalink: /legal-notice/
+description: The legal notice for this website can be found here.
 ---
 
 <h2>Information provided according to Sec. 5 German Telemedia Act (TMG):</h2>

pages/privacy-policy.html

@@ -1,6 +1,7 @@
 ---
 title: Privacy Policy
 permalink: /privacy-policy/
+description: The privacy policy for this website can be found here.
 ---
 
 <h2>Data Protection</h2>

pages/snowden-refugees.html

@@ -2,6 +2,7 @@
 title: Snowden Refugees
 permalink: /snowden-refugees/
 sidebarboxes: snowden-refugees encrypted-communication
+description: The Snowden Refugees helped Edward Snowden in 2013. They had nothing and gave everything. Here you can find out how to help them.
 ---
 
 <p>

politics/g20/index.html

@@ -4,6 +4,7 @@ title: G20
 category: G20
 sidebarboxes: author politics_qanda encrypted-communication
 parent_link: /politics/
+description: This page collects all the reports from the G20 special committee of the Hamburg Parliament.
 ---
 
 <h1>G20</h1>

politics/index.html

@@ -3,6 +3,7 @@ layout: category
 title: Politics
 category: politics
 sidebarboxes: author politics_qanda encrypted-communication
+description: All my political activities and related blog posts can be found on this page.
 ---
 
 <h1>Politics</h1>

speeches/index.html

@@ -2,6 +2,7 @@
 layout: category
 title: Speeches
 category: speeches
+description: This page provides an overview over all my speeches.
 ---
 
 <h1>Speeches</h1>