Point users to Matrix/Vector bridge for IRC access

Update ruby support for histograms

Add Julius to commercial support section

At least for the moment...

Unit examples should be seconds

Blog post: "Pull does not scale - or does it?"

Add grok_exporter

Add some CNCF branding.

Clarify DNS service discovery relationship to DNS-SD

It's a common misconception to call any DNS SRV record based discovery
approach "DNS-SD". The latter is a [ratified IETF standard][rfc6763]
which specifies a naming schema and lookup mechanism in order to provide
additional structured information. Prometheus only supports basic SRV
record lookups.

[rfc6763]: https://tools.ietf.org/html/rfc6763

Emphasize the cumulative nature of a histogram.

Link the relevant Wikipedia entry.

Add reference to PHP client library

Slightly improve wording about series cardinality

Replaces deprecated `scrape_configs` in examples

According to https://prometheus.io/docs/operating/configuration/ the `target_groups` field was replaced by `static_configs`.

Remove merge conflict leftover from k8s docs

Add 1.0 announcement news bar.

Revert this after we feel that the news is not hot anymore.

Merge next release for 1.0

Fix stable/unstable list headers in 1.0 post