Update README.md

README.md

 # vcf_stats
 ## Stats for VCF files in standalone HTML5
 http://sauloal.github.io/vcf_stats/
+
 ## Example
 http://htmlpreview.github.io/?http://cdn.rawgit.com/sauloal/vcf_stats/master/vcf_stats_report.py_report.html
+
+### Run
+input file1.vcf file2.vcf filen.vcf
+```
+pyhton vcf_stats.py file1.vcf file2.vcf filen.vcf
+```
+output file1.vcf.json file2.vcf.json filen.vcf.json
+```
+python vcf_stats_report.py file1.vcf.json file2.vcf.json filen.vcf.json
+```
+output vcf_stats_report.py_report.html
+```
+open vcf_stats_report.py_report.html in your browser and select the desired file to see the report.
+```