Improve documentation for AnnotateVcfWithBed

docs/tools/AnnotateVcfWithBed.md

 # AnnotateVcfWithBed 
 
 ## Introduction
- This tool to annotates a vcf file with input from a bed file
+ This tool to annotates a vcf file using the input from a bed file
 
 ## Example
 To get the help menu:
@@ -28,7 +28,7 @@ Usage: AnnotateVcfWithBed [options]
         Description of field in new vcf file
 ~~~
 
-To run the tool:
+To run the tool use:
 ~~~
 biopet tool AnnotateVcfWithBed -I myVcf.vcf -B myBed.bed -o myannotatedVcf.vcf  
 ~~~