Merge pull request #6 from andrew-demb/readme

Readme nitpicks

Author: allflame

README.md

@@ -1,19 +1,23 @@
-
 # PHP OpenTracing API using Jaeger 
 
-
 ## Installation
 
-```
+```bash
 composer require code-tool/jaeger-client-php
 ```
 
 ## Getting Started
 
-It is strictly advised to use any form of DI container (e.g. [Symfony](https://github.com/code-tool/jaeger-client-symfony-bridge)).
-```$xslt
+It is strictly advised to use any form of DI container (e.g. [Symfony Bundle](https://github.com/code-tool/jaeger-client-symfony-bridge)).
+
+```php
 <?php
 
+use Jaeger\Tag\StringTag;
+use Jaeger\Tracer\TracerInterface;
+
+/** @var TracerInterface $tracer */
+
 $span = $tracer->start('Parent Operation Name', [new StringTag('test.tag', 'Hello world in parent')]);
 $childSpan = $tracer->start('Child Operation Name', [new StringTag('test.tag', 'Hello world in child')]);
 $tracer->finish($childSpan);