Documentated, added feature.

- Toggle All Sync (command) for suspend all sync.
- Batch database update (beta)

docs/tech_info.md

@@ -0,0 +1,16 @@
+# Designed architecture
+
+## How does this plugin synchronize.
+
+![Synchronization](../images/1.png)
+
+1. When notes are created or modified, Obsidian raises some events. Self-hosted LiveSync catches these events and reflects changes into Local PouchDB.
+2. PouchDB automatically or manually replicates changes to remote CouchDB.
+3. Another device is watching remote CouchDB's changes, so retrieve new changes.
+4. Self-hosted LiveSync reflects replicated changeset into Obsidian's vault.
+
+Note: The figure is drawn as single-directional, between two devices. But everything occurs bi-directionally between many devices at once in real.
+
+## Techniques to keep bandwidth low.
+
+![dedupe](../images/2.png)