Add security policy for file syncing

[spbrogan]

Will provide the solution that closes or resolves:

• https://github.com/microsoft/mu/issues/130
• https://github.com/microsoft/mu_basecore/issues/141
• https://github.com/microsoft/mu_basecore/pull/109
• https://github.com/microsoft/mu_plus/issues/74
• https://github.com/microsoft/mu_plus/pull/48
• https://github.com/microsoft/mu_tiano_plus/issues/46
• https://github.com/microsoft/mu_tiano_plus/pull/19
• https://github.com/microsoft/mu_oem_sample/issues/15
• https://github.com/microsoft/mu_oem_sample/pull/7
• https://github.com/microsoft/mu_silicon_arm_tiano/issues/21
• https://github.com/microsoft/mu_silicon_arm_tiano/pull/15
• https://github.com/microsoft/mu_silicon_intel_tiano/issues/17
• https://github.com/microsoft/mu_silicon_intel_tiano/pull/7
• https://github.com/microsoft/mu_feature_mm_supv/issues/16
• https://github.com/microsoft/mu_feature_mm_supv/pull/5
• https://github.com/microsoft/mu_crypto_release/pull/4
• https://github.com/microsoft/mu_common_intel_min_platform/pull/43
• https://github.com/microsoft/mu_common_intel_min_platform/issues/67