docs: general documentation rework

- restructures the docs to make them easier to explore
- rewrites promtail docs
- unifies, shortens and extends docs

docs/index.md

@@ -0,0 +1,34 @@
+<p align="center">
+  <img src="logo_and_name.png" alt="Loki Logo"> <br>
+  <small>Like Prometheus, but for logs!</small>
+</p>
+
+Grafana Loki is a set of components, that can be composed into a fully featured logging stack.
+
+It builds around the idea of treating a single log line as-is. This means that
+instead of full-text indexing them, related logs are grouped using the same labels
+as in Prometheus. This is much more efficient and scales better.
+
+## Components
+- **[Loki](loki/overview.md)**: The main server component is called Loki. It is responsible for
+  permanently storing the logs it is being shipped and it executes the LogQL
+  queries from clients.  
+  Loki shares its high-level architecture with Cortex, a highly scalable
+  Prometheus backend.
+- **[Promtail](promtail/overview.md)**: To ship logs to a central place, an agent is required. Promtail
+  is deployed to every node that should be monitored and sends the logs to Loki.  
+  It also does important task of pre-processing the log lines, including
+  attaching labels to them for easier querying.
+- *Grafana*: The *Explore* feature of Grafana 6.0+ is the primary place of
+  contact between a human and Loki. It is used for discovering and analyzing logs.
+
+Alongside these main components, there are some other ones as well:
+
+- **[LogCLI](logcli.md)**: A command line interface to query logs and labels from Loki
+- **Canary**: An audit utility to analyze the log-capturing performance of Loki.
+  Ingests data into Loki and immediately reads it back to check for latency and loss.
+- **Docker Driver**: A Docker [log driver](https://docs.docker.com/config/containers/logging/configure/) to ship logs captured by Docker
+  directly to Loki, without the need of an agent.
+- **Fluentd Plugin**: An Fluentd [output
+  plugin](https://docs.fluentd.org/output), to use Fluentd for shipping logs
+  into Loki

docs/logcli.md

@@ -1,23 +1,25 @@
-# Log CLI usage Instructions
+# LogCLI
 
-Loki's main query interface is Grafana; however, a basic CLI is provided as a proof of concept.
-
-Once you have Loki running in a cluster, you can query logs from that cluster.
+LogCLI is a handy tool to query logs from Loki without having to run a full Grafana instance.
 
 ## Installation
 
-### Get latest version
+### Binary (Recommended)
+Head over to the [Releases](https://github.com/grafana/loki/releases) and download the `logcli` binary for your OS:
+```bash
+# download a binary (adapt app, os and arch as needed)
+# installs v0.2.0. For up to date URLs refer to the release's description
+$ curl -fSL -o "/usr/local/bin/logcli.gz" "https://github.com/grafana/logcli/releases/download/v0.2.0/logcli-linux-amd64.gz"
+$ gunzip "/usr/local/bin/logcli.gz"
 
-```
-$ go get github.com/grafana/loki/cmd/logcli
+# make sure it is executable
+$ chmod a+x "/usr/local/bin/logcli"
 ```
 
-### Build from source
+### From source
 
 ```
-$ go get github.com/grafana/loki
-$ cd $GOPATH/src/github.com/grafana/loki
-$ go build ./cmd/logcli
+$ go get github.com/grafana/loki/cmd/logcli
 ```
 
 Now `logcli` is in your current directory.
@@ -36,14 +38,15 @@ Otherwise, when running e.g. [locally](https://github.com/grafana/loki/tree/mast
 ```
 $ export GRAFANA_ADDR=http://localhost:3100
 ```
-> Note: If you are running loki behind a proxy server and have an authentication setup. You will have to pass URL, username and password accordingly. Please refer to the [docs](https://github.com/adityacs/loki/blob/master/docs/operations.md) for more info.
+> Note: If you are running loki behind a proxy server and have an authentication setup, you will have to pass URL, username and password accordingly. Please refer to [Authentication](loki/operations.md#authentication) for more info.
 
-```
+```bash
 $ logcli labels job
 https://logs-dev-ops-tools1.grafana.net/api/prom/label/job/values
 cortex-ops/consul
 cortex-ops/cortex-gw
 ...
+
 $ logcli query '{job="cortex-ops/consul"}'
 https://logs-dev-ops-tools1.grafana.net/api/prom/query?query=%7Bjob%3D%22cortex-ops%2Fconsul%22%7D&limit=30&start=1529928228&end=1529931828&direction=backward&regexp=
 Common labels: {job="cortex-ops/consul", namespace="cortex-ops"}
@@ -55,14 +58,14 @@ Common labels: {job="cortex-ops/consul", namespace="cortex-ops"}
 
 Configuration values are considered in the following order (lowest to highest):
 
-- environment value
-- command line
+- Environment variables
+- Command line flags
 
 The URLs of the requests are printed to help with integration work.
 
 ### Details
 
-```console
+```bash
 $ logcli help
 usage: logcli [<flags>] <command> [<args> ...]