chore(doc-gen): improve github links to point to the correct tagged URL

Closes #1994

docs/angular.io-package/templates/class.template.html

@@ -1,10 +1,11 @@
+{% include "lib/githubLinks.html" -%}
 {% include "lib/paramList.html" -%}
 {% extends 'layout/base.template.html' -%}
 
 {% block body %}
 p.location-badge.
   exported from {@link {$ doc.moduleDoc.id $} {$doc.moduleDoc.id $} }
-  defined in <a href="https://github.com/angular/angular/tree/master/modules/{$ doc.fileInfo.relativePath $}#L{$ doc.location.start.line+1 $}-L{$ doc.location.end.line+1 $}">{$ doc.fileInfo.relativePath $} (line {$ doc.location.start.line+1 $})</a>
+  defined in {$ githubViewLink(doc) $}
 
 :markdown
 {$ doc.description | indent(2, true) $}

docs/angular.io-package/templates/function.template.html

@@ -1,3 +1,4 @@
+{% include "lib/githubLinks.html" -%}
 {% include "lib/paramList.html" -%}
 {% extends 'layout/base.template.html' -%}
 
@@ -13,7 +14,7 @@
 
   p.location-badge.
     exported from {@link {$ doc.moduleDoc.id $} {$doc.moduleDoc.id $} }
-    defined in <a href="https://github.com/angular/angular/tree/master/modules/{$ doc.fileInfo.relativePath $}#L{$ doc.location.start.line+1 $}-L{$ doc.location.end.line+1 $}">{$ doc.fileInfo.relativePath $} (line {$ doc.location.start.line+1 $})</a>
+    defined in {$ githubViewLink(doc) $}
 
   :markdown
 {$ doc.description | indent(4, true) $}

docs/angular.io-package/templates/module.template.html

@@ -1,7 +1,8 @@
+{% include "lib/githubLinks.html" -%}
 {% extends 'layout/base.template.html' -%}
 {% block body -%}
 p.location-badge.
-  defined in <a href="https://github.com/angular/angular/tree/master/modules/{$ doc.fileInfo.relativePath $}#L{$ doc.location.start.line+1 $}-L{$ doc.location.end.line+1 $}">{$ doc.fileInfo.relativePath $} (line {$ doc.location.start.line+1 $})</a>
+  defined in {$ githubViewLink(doc) $}
 
 ul
   for page, slug in public.docs[current.path[1]][current.path[2]][current.path[3]][current.path[4]]._data

docs/angular.io-package/templates/var.template.html

@@ -1,3 +1,4 @@
+{% include "lib/githubLinks.html" -%}
 {% extends 'layout/base.template.html' %}
 
 {% block body %}
@@ -5,6 +6,7 @@
   h2 {$ doc.name $} <span class="type">variable</span>
   p.location-badge.
     exported from {@link {$ doc.moduleDoc.id $} {$doc.moduleDoc.id $} }
+    defined in {$ githubViewLink(doc) $}
 
   :markdown
 {$ doc.description | indent(4, true) $}