Basic support for metrics

config.sample.yaml

...urt2live/matrix-media-repo/api/webserver/route_handler.go

...om/turt2live/matrix-media-repo/api/webserver/webserver.go

...ub.com/turt2live/matrix-media-repo/cmd/media_repo/main.go

...b.com/turt2live/matrix-media-repo/common/config/config.go

...trollers/download_controller/download_resource_handler.go

...ers/preview_controller/previewers/calculated_previewer.go

...lers/preview_controller/previewers/opengraph_previewer.go

...ollers/thumbnail_controller/thumbnail_resource_handler.go

...turt2live/matrix-media-repo/internal_cache/media_cache.go

...github.com/turt2live/matrix-media-repo/metrics/metrics.go

...thub.com/turt2live/matrix-media-repo/metrics/webserver.go

vendor/manifest