app-text/zathura-meta: improve metadata

- add remote-id
- fix bugs-to, doc & changelog
- fix indentation

Signed-off-by: Filip Kobierski <fkobi@pm.me>
Signed-off-by: Florian Schmaus <flow@gentoo.org>

app-text/zathura-meta/metadata.xml

@@ -15,8 +15,9 @@
       <email>sebastian+dev@ramacher.at</email>
       <name>Sebastian Ramacher</name>
     </maintainer>
-    <changelog>http://pwmt.org/projects/zathura/download/</changelog>
-    <doc lang="en">http://pwmt.org/projects/zathura/</doc>
-    <bugs-to>http://bugs.pwmt.org/</bugs-to>
+    <bugs-to>https://github.com/pwmt/zathura/issues</bugs-to>
+    <changelog>https://pwmt.org/projects/zathura/download/</changelog>
+    <doc>https://pwmt.org/projects/zathura/documentation/</doc>
+    <remote-id type="github">pwmt/zathura</remote-id>
   </upstream>
 </pkgmetadata>