libraries-bom usage docs for end users (#1134)
libraries-bom usage docs for end users (#1134)

* move DECLARING_DEPENDENCIES.md onto jlbp.dev

* move DECLARING_DEPENDENCIES.md onto jlbp.dev

* Remove libaries we don't explicitly declare.

* restore original

* remove bad link

* more libraries

* more libraries

* more libraries

* code review

GoogleCloudPlatform/cloud-opensource-java,GoogleCloudPlatform/cloud-opensource-java,GoogleCloudPlatform/cloud-opensource-java