Adding support for custom patterns in filecontent detection

#183 Custom patterns  (#187)

* Rename TalismanRCIgnore to TalismanRC

* Code cleanup:
Rename NewtalismanRC to NewTalismanRC
Remove code and tests related to talismanignore

* Code cleanup: Make talismanRC receiver name consistent

* Introduce PatternString type
Omit empty fields when writing yaml

* #183 | Add ability to specify custom scan pattern via talismanrc

* Update Readme:
Update help text for CLI options (fix typo in -i message description)
Add custom_pattern section with example

Hacktoberfest contributions

• Performance improvements
• Talisman binary can be invoked in interactive mode to updated talismanrc

Add feature to permanently ignore files based on a scope

Talisman now supports permanently ignoring certain files using an idea called scopes.
A scope defines a set of files that will be ignored by talisman during scans.
There a currently a few hard-coded set of scopes (node, go to support nodeJS and Go-lang respectively). Users cannot create their own scopes.
A guideline for adding scopes vi github Pull Request's is being prepared.

Added scanning for a new pattern PWD=xxxxxxxx

Merge pull request #131 from harinee/master

Deleting .talismanignore as it is deprecated now

Fixed recurring update issue

v0.4.9

Fixed Talisman header in readme

Talisman HTML reporting is now active

This release introduces talisman scan reports in HTML

v0.4.7: Merge pull request #121 from jaydeepc/master

Changed the Author Name, no code changes included

Fixed scan logic when checksum is not matching

This release fixes a bug in the scanning logic of Talisman

Adds summary section to JSON in scan report

• Now the summary section in JSON report is populated
• Code has been refactored to accommodate further changes

Generate scan report in JSON and modify the scan logic

• Now, users can generate scan report in JSON format and store it in a custom location
• The scan logic has now been updated to scan only the diff for each file if Talisman is being used as a pre-commit hook.
• Stops the scan in scenarios where the checksum of the file is matching