Add exporter for Mozilla Observatory
Add exporter for Mozilla Observatory

Adding the prometheus exporter for Mozilla Observatory to docs
Cepave/openfalcon.io,prometheus/docs,Cepave/openfalcon.io,du2016/prometheus-docs,ddfreyne/prometheus-docs,chosenken/docs,chosenken/docs,open-falcon/open-falcon.github.io,chosenken/docs,ddfreyne/prometheus-docs,prometheus/docs,ddfreyne/prometheus-docs,prometheus/docs,ddfreyne/prometheus-docs,du2016/prometheus-docs,Cepave/openfalcon.io,open-falcon/open-falcon.github.io,open-falcon/open-falcon.github.io,du2016/prometheus-docs,chosenken/docs