build: tagging releases with 'latest' tag (#19)

* build: tagging releases with 'latest' tag
* docs: use latest tag in readme

docs: add remark on v0.113.4 main change (#18)

docs: Update CHANGELOG.md (#10)

[feature] Solarwinds Extension (#4)

* Add SolarWinds Extension providing collector heartbeat and integrate SolarWinds Exporter to obtain configuration from the extension.
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Co-authored-by: Marek Simek <[email protected]>