added type front matter

[hblankenship]

Added type field for front matter which should be one of : documentation, tool, or code

Thank you for submitting a Pull Request to the Mobile Security Testing Guide project website. Please make sure that:

• [ ] Your contribution is written in the 2nd person (e.g. you)
• [ ] Your contribution is written in an active present form for as much as possible.
• [ ] Your contribution has proper formatted markdown and/or code
• [ ] Any references to website have been formatted as [TEXT](URL “NAME”)

If your PR is related to an issue. Please end your PR test with the following line: This PR covers issue #< insert number here >.

[commjoen]

thaks!