feat(docs): Give the README a once-over refresh

A lot has changed since the README has been read from top to bottom.
This change does a bit of a refresh on the README: improving formatting,
adding more context, removing some info that is no longer relevant, etc.

More could definitely be done, especially following up on the list of
parameters and configuration options for test suites and test cases.

README.md

@@ -2,20 +2,19 @@
 
 [![Greenkeeper badge](https://badges.greenkeeper.io/pelias/fuzzy-tester.svg)](https://greenkeeper.io/)
 
-This is the Pelias fuzzy tester library, used for running our
+This is the Pelias fuzzy tester library, used for testing the [Pelias Geocoder](https://github.com/pelias/pelias) by running our
 [acceptance-tests](https://github.com/pelias/acceptance-tests) and
 [fuzzy-tests](https://github.com/pelias/fuzzy-tests).
 
-What are fuzzy tests? See the original [problem statement](https://github.com/pelias/acceptance-tests/issues/109)
-that lead to the creation of this library.
+Unlike a traditional unit test suite, testing a geocoder requires a bit of flexibility for many reasons:
+- data can change
+- minor differences in expected output should be handled
+- it may not be feasible to fix certain errors at a certain time.
+- The number of test cases is extremely large
 
-Most importantly, fuzzy tests deliver more than just a single bit of pass or fail for each test:
-they specify a total number of points (a score) for the test, and return how many points out of the
-maximum were achieved. The weighting of individual parts of the test can be adjusted.
+For more info on the challenges,see the original [problem statement](https://github.com/pelias/acceptance-tests/issues/109)
+that lead to the creation of this library.
 
-**Note:** fuzzy-tester requires NPM version 2 or greater. The NPM team
-[recommends](http://blog.npmjs.org/post/85484771375/how-to-install-npm) you update NPM using NPM
-itself with `sudo npm install -g npm`.
 ## Example Usage
 
 ```
@@ -103,15 +102,15 @@ AWS account, and that your `pelias-config` file contain the following configurat
 
 ```javascript
 {
-	"acceptance-tests": {
-		"email": {
-			"ses": {
-				"accessKeyId": "AWSACCESSKEY",
-				"secretAccessKey": "AWS/Secret/key",
-			},
-			"recipients": ["[email protected]", "[email protected]"], // the list of recipients
-		}
-	}
+  "acceptance-tests": {
+    "email": {
+      "ses": {
+        "accessKeyId": "AWSACCESSKEY",
+        "secretAccessKey": "AWS/Secret/key",
+      },
+      "recipients": ["[email protected]", "[email protected]"], // the list of recipients
+    }
+  }
 }
 ```
 
@@ -135,17 +134,18 @@ case. This helps detect situations where one expectation is found, but the other
 red `0` in that case).
 
 ## API URL aliases
+
 The acceptance-tests runner recognizes a number of aliases for Pelias API URLs (eg, `stage` corresponds to
 `pelias.stage.mapzen.com`), which can be specified as command-line arguments when running a test suite. You can
 override the default aliases and define your own in `pelias-config`:
 
 ```javascript
 {
-	"acceptance-tests": {
-		"endpoints": {
-			"alias": "http://my.pelias.instance"
-		}
-	}
+  "acceptance-tests": {
+    "endpoints": {
+      "alias": "http://my.pelias.instance"
+    }
+  }
 }
 ```