Add README with requirements and usage guide

Author: DifferentialOrange

README.md

@@ -1,2 +1,43 @@
-# tarantool-dashboard
-tarantool grafana dashboard
+# Tarantool Grafana dashboard
+
+## Requirements and setup
+
+1. Install [go-jsonnet](https://github.com/google/go-jsonnet) compiler. We use v0.16.0. 
+
+1. Install [jsonnet-bundler](https://github.com/jsonnet-bundler/jsonnet-bundler) package manager.
+
+1. Install jsonnet package dependencies with ```jb install```.
+
+## Experimantal cluster
+
+```docker-compose up -d``` will start 5 containers: Tarantool, Telegraf, InfluxDB, Prometheus and Grafana, which build cluster with two fully operational metrics datasources (InfluxDB and Prometheus), extracting metrics from Tarantool instance. We recommend using the exact versions we use in experimental cluster (e.g. Grafana v6.6.0). 
+
+## Usage
+
+Currently we provide only InfluxDB-based dashboard template. 
+
+### InfluxDB dashboard
+
+* Compile board template with
+```bash
+jsonnet -J ./vendor/ ./tarantool/dashboard.libsonnet -o ./output.json
+```
+to save json template into `output.json` file or
+```bash
+jsonnet -J ./vendor/ ./tarantool/dashboard.libsonnet | xclip -selection clipboard
+```
+to put json template into clipboard.
+
+* Open Grafana import menu.
+
+![Grafana import button in v6.6.0](./docs/grafana_import_v6.png)
+
+* Paste json template from clipboard or upload json template file.
+
+* Set dashboard name, folder, uid (if needed), InfluxDB source and measurement of your project's metrics.
+
+![Grafana import setup in v6.6.0](./docs/grafana_import_setup_v6.png)
+
+## Tests
+
+You can run tests with `./tests.sh` script. `jsonnet` and `jsonnetfmt` must be added to terminal PATH variable.