Organize plans/specs

diff --git a/release_plan.md b/plans/release_plan.md
similarity index 100%
rename from release_plan.md
rename to plans/release_plan.md

diff --git a/technical_release_plan.md b/plans/technical_release_plan.md
similarity index 100%
rename from technical_release_plan.md
rename to plans/technical_release_plan.md

diff --git a/backend_database_specification.md b/specifications/backend_database_specification.md
similarity index 100%
rename from backend_database_specification.md
rename to specifications/backend_database_specification.md

diff --git a/backend_protocol_specification.md b/specifications/backend_protocol_specification.md
similarity index 100%
rename from backend_protocol_specification.md
rename to specifications/backend_protocol_specification.md