Added doc structure plan

Author: Joel Collins

docs/plan.md

@@ -0,0 +1,67 @@
+# Documentation plan/structure
+
+## Basic usage
+
+* create_app
+* LabThing class
+* Server class
+* current_labthing
+
+### HTTP API structure
+
+* Thing Description (root)
+* Swagger-UI
+* Action queue
+* Extension list
+
+### WebSocket API structure
+
+* Not yet implemented
+
+### Serialising data
+
+* fields
+* schema
+* semantics
+
+### Action tasks
+
+* Preamble (all actions are tasks, etc)
+* Labthing.actions TaskPool
+* current_task
+* update_task_progress
+* update_task_data
+* Stopping tasks
+  * TaskThread.stopped event
+  * TaskKillException
+
+### Synchronisation
+
+* StrictLock
+* CompositeLock
+* ClientEvent
+
+## Advanced usage
+
+### View classes
+
+* labthings.views
+  
+### Components
+
+* Access to Python objects by name
+  * Used to access hardware from within Views
+* registered_components, find_component
+
+### Encoders
+
+* labthings.json.LabThingsJSONEncoder
+
+## Extension system
+
+* labthings.extensions.BaseExtension
+* labthings.extensions.find_extensions
+
+### Find functions
+
+* registered_extensions, find_extension