~artemis/paste

removed server-side syntaxic coloration, wontfix
Uniformized error pages
fixed form error styling
Added text trimming
finished changing routing
Integrated main templates and started designing new view mode switch, noted TODOs
Cleaned a bit, uniformized handlers
Merge branch 'feature/go-refactor' into 'master'

Feature/go refactor

See merge request Artemix/paste!1
Documented new release
Integrated new search bar design for view mode toggle
Integrated markdown rendering
Finished stylizing generic error page
Documented unit used for memory usage check
Fixed error handling
WIP: Integrated Prometheus stats
Documented CLI arg
Added CLI args
Added type checks
Fixed validation / deserialization
Cleaned up error management
Next