Add decision header for Prometheus vs. InfluxDB

docs/adr/adr-010-incentivized-testnet-monitoring.md

@@ -28,7 +28,11 @@ Grafana can query data from [multiple data sources](https://grafana.com/docs/gra
 1. [Prometheus](https://github.com/prometheus/prometheus) is an open-source time series database written in Go. Prometheus uses the [PromQL](https://prometheus.io/docs/prometheus/latest/querying/basics/) query language. We can deploy Prometheus ourselves or use a hosted Prometheus provider (ex. [Google](https://cloud.google.com/stackdriver/docs/managed-prometheus), [AWS](https://aws.amazon.com/prometheus/), [Grafana](https://grafana.com/go/hosted-prometheus-monitoring/), etc.). Prometheus is pull-based which means services that would like to expose Prometheus metrics must provide an HTTP endpoint (ex. `/metrics`) that a Prometheus instance can poll (see [instrumenting a Go application for Prometheus](https://prometheus.io/docs/guides/go-application/)). Prometheus is used by [Cosmos SDK telemetry](https://docs.cosmos.network/main/core/telemetry.html) and [Tendermint telemetry](https://docs.tendermint.com/v0.35/nodes/metrics.html) so one major benefit to using Prometheus is that metrics emitted by celestia-core, celestia-app, and celestia-node can share the same database.
 2. [InfluxDB](https://github.com/influxdata/influxdb) is another open-source time series database written in Go. It is free to deploy the InfluxDB but there is a commercial offering from [influxdata](https://www.influxdata.com/get-influxdb/) that provides clustering and on-prem deployments. InfluxDB uses the [InfluxQL](https://docs.influxdata.com/influxdb/v1.8/query_language/) query language which appears less capable at advanced queries [ref](https://www.robustperception.io/translating-between-monitoring-languages/). InfluxDB is push-based which means services can push metrics directly to an InfluxDB instance ([ref](https://logz.io/blog/prometheus-influxdb/#:~:text=InfluxDB%20is%20a%20push%2Dbased,and%20Prometheus%20fetches%20them%20periodically.)). See [Prometheus vs. InfluxDB](https://prometheus.io/docs/introduction/comparison/#prometheus-vs-influxdb) for a more detailed comparison.
 
-If alternative data sources should be evaluated, please share them with us. We propose using Prometheus at this time.
+If alternative data sources should be evaluated, please share them with us.
+
+#### Decision
+
+We agreed to using Prometheus at this time.
 
 ### How to export data out of OTEL Collector?