Updates to resources

Consolidated courses into a single section. Added dedicated area for consumer-app provided documentation. Resolves https://github.com/MobilityData/awesome-transit/issues/174.

README.md

@@ -42,11 +42,24 @@ Have something to add or change? Open a [pull request](https://github.com/Mobili
 
 ### Reference resources
 
-- [GTFS.org](https://gtfs.org) official documentation site for the General Transit Feed Specification. Includes additional GTFS resources.
-- [Google Transit Developers](https://developers.google.com/transit/gtfs/) additional Google-specific documentation of GTFS.
-- [World Bank: Intro. to GTFS](https://olc.worldbank.org/content/introduction-general-transit-feed-specification-gtfs-and-informal-transit-system-mapping) free, online, self-paced course for learning about GTFS and GTFS Realtime.
-- [MBTA GTFS Onboarding](https://mybinder.org/v2/gh/mbta/gtfs_onboarding/main?urlpath=lab/tree/GTFS_Onboarding.ipynb) an interactive tutorial created by MBTA for GTFS static. A [stand-alone Docker image](https://github.com/mbta/gtfs_onboarding) is available on GitHub as well as a [hosted/no-install version](https://mybinder.org/v2/gh/mbta/gtfs_onboarding/main?urlpath=lab/tree/GTFS_Onboarding.ipynb) of the Jupyter notebook.
-- [TransitWiki](http://transitwiki.org) community wiki for transit planners. Like this repo, but better.
+- [GTFS.org](https://gtfs.org) official documentation site for the General Transit Feed Specification.
+
+#### Consumer app guidance
+
+- [Google Transit Developers](https://developers.google.com/transit/gtfs/) - Additional Google-specific documentation of GTFS.
+- [Transit app Guidelines for Producing GTFS Static Data](https://resources.transitapp.com/article/458-guidelines-for-producing-gtfs-static-data-for-transit) - Additional Transit app-specific documentation of GTFS.
+- [Bing Maps Transit - Add your transit data to Bing Maps](https://www.bing.com/maps/transitcontentproviders) - Additional Bing-specific documentation of GTFS.
+- [Yandex Maps - Transport integration](https://yandex.ru/support/m-maps/transport.html?lang=en#connect-display) - Additional Yandex-specific documentation of GTFS.
+
+#### Courses
+
+- [MobilityData - "Understanding GTFS: An intro and overivew](https://www.youtube.com/watch?v=SDz2460AjNo) - Video provides an overview of of the General Transit Feed Specification (GTFS) and why it is useful for transit agencies, riders, and policymakers. 
+- [World Bank - "Intro. to GTFS" online course](https://olc.worldbank.org/content/introduction-general-transit-feed-specification-gtfs-and-informal-transit-system-mapping) - A free, online, self-paced course for learning about GTFS and GTFS-realtime.
+- [Open Transit Data Toolkit](http://transitdatatoolkit.com/) - A series of lessons to help people utilize open transit data.
+- [ArcGIS - Introduction to GTFS](https://www.youtube.com/watch?v=8OQKHhu1VgQ&t=148s)
+- [GTFS-books](https://github.com/MobilityData/GTFS-books) - Comprehensive guides to GTFS and GTFS Realtime. These books were written by [Quentin Zervaas](https://github.com/HendX), and have been donated to [MobilityData](https://mobilitydata.org/) and made open access.
+- [MBTA GTFS Onboarding](https://mybinder.org/v2/gh/mbta/gtfs_onboarding/main?urlpath=lab/tree/GTFS_Onboarding.ipynb) - An interactive tutorial created by MBTA for GTFS static. A [stand-alone Docker image](https://github.com/mbta/gtfs_onboarding) is available on GitHub as well as a [hosted/no-install version](https://mybinder.org/v2/gh/mbta/gtfs_onboarding/main?urlpath=lab/tree/GTFS_Onboarding.ipynb) of the Jupyter notebook.
+- [Planetizen "Building a Transit Map Web App" course](https://courses.planetizen.com/course/building-transit-map-app) - A video tutorial on setting up your own web-based mapping application, with no coding experience required. 
 
 ### Community
 
@@ -549,18 +562,9 @@ Massachusetts Bay Transportation Authority (MBTA)](https://github.com/mbta).
 - [Cal-ITP Operational Data Standard (ODS)](https://docs.calitp.org/operational-data-standard/) -  Intended to address the lack of a standard format for representing transit schedules used by drivers, dispatchers, and planners to carry out transit operations. 
 - [Transport Operator Mobility-as-a-service Provider (TOMP)-API](https://github.com/TOMP-WG/TOMP-API) - Working group in the Netherlands with a goal to develop an API for use by Transport Operators and Mobility-as-a-service Providers for operator discovery, trip planning, end user interaction, booking, and payment.
 
-### Resources
-
-On-line courses, blog posts, and reports related to open transit data.
-
-#### On-line courses
-
-- [World Bank - "Intro. to GTFS" online course](https://olc.worldbank.org/content/introduction-general-transit-feed-specification-gtfs-and-informal-transit-system-mapping) - A free, online, self-paced course for learning about GTFS and GTFS-realtime.
-- [Open Transit Data Toolkit](http://transitdatatoolkit.com/) - A series of lessons to help people utilize open transit data.
-- [MBTA GTFS Onboarding](https://mybinder.org/v2/gh/mbta/gtfs_onboarding/main?urlpath=lab/tree/GTFS_Onboarding.ipynb) - An interactive tutorial created by MBTA for GTFS static. A [stand-alone Docker image](https://github.com/mbta/gtfs_onboarding) is available on GitHub as well as a [hosted/no-install version](https://mybinder.org/v2/gh/mbta/gtfs_onboarding/main?urlpath=lab/tree/GTFS_Onboarding.ipynb) of the Jupyter notebook.
-- [Planetizen "Building a Transit Map Web App" course](https://courses.planetizen.com/course/building-transit-map-app) - A video tutorial on setting up your own web-based mapping application, with no coding experience required. 
-- [GTFS-books](https://github.com/MobilityData/GTFS-books) - Comprehensive guides to GTFS and GTFS Realtime. These books were written by [Quentin Zervaas](https://github.com/HendX), and have been donated to [MobilityData](https://mobilitydata.org/) and made open access.
+### Research and Commentary
 
+Blog posts, and reports related to open transit data.
 
 #### Blog posts