GTFS Feature Changes

[emmambd]

Describe the problem

GTFS feature changes to reflect comments in #1812

Proposed solution

• Change Fares Transfers to Fare Transfers
• Change Frequency-Based Service to Frequencies
• Change logic of Pathway Signs to "One signposted_as value OR one reversed_signposted_as in pathways.txt"
• URL changes for Frequencies and Fare Transfers as reflected in https://github.com/MobilityData/gtfs-validator/blob/master/docs/FEATURES.md

Alternatives you've considered

No response

Additional context

No response