add option to load template profile.

[ehsandeep]

   -tp, -profile string              template profile config file to run

EXAMPLE Runs:

nuclei -profile profiles/aws-cloud-config.yml # loads profile from installed template directory
nuclei -profile aws-cloud-config # loads profile from installed template directory using file name as id
nuclei -profile /Users/geekboy/profiles/custom_profile.yml # loads profile based on given config file

[princechaddha]

can add -tpl, -profiles-list similar to -tl for listing down all the available profiles from ~/nuclei-templates/profiles