Restructure Overlay Attribution Credits

[adambreznicky]

Currently all overlay data supplied by LCRA and the first round of lakes will all be in Region K with overlay data supplied by LCRA so the layer 'attributes' credit is hard coded for LCRA.

Need to update this to a dynamic system when the lake content expands more statewide (outside Region K) and overlay data is sourced from other entities.

[jwhaney]

with the code refactoring in the upcoming v2 update, which includes transitioning to geojson layers from tile layers, i think this issue is obsolete. also, regions and many other layers that were in each story map layer control are no longer included.

will wait to discuss this with @adambreznicky to see if this can be closed.