add ascii communication diagram

README.md

@@ -51,6 +51,31 @@ The appliction is implemented using the following different components:
   - When a user logs in with the `dooris` user now, they are always dropped into the `ssh-cli` binary. This works in cases where a command is specified on the users cli or where it isn't.
     In any case, the `ssh-cli` binary interprets the given command (via the `SSH_ORIGINAL_COMMAND` environment variable), figures out what to do, and contacts the running API with the configured credentials to do it.
 
+### Communication Diagram
+
+```text
+┌─────────────────┐           ┏━━━━━━━━━━━━━━┓ 
+│   web browser   │           ┃  dooris-api  ┃
+├┈┈┈┈┈┈┈with┈┈┈┈┈┈┤           ┣┉┉┉┉┉with┉┉┉┉┉┫             ┌──────────┐
+│ dooris-frontend │ ╌ ╌ ⇆ ╌ ╌ ┃  http server ┃ ╭ ╌ ╌ → ╌ ╌ │ SpaceApi │
+└─────────────────┘        ╭╌ ┃              ┃ ╎           └──────────┘
+                           ╎  ┣┉┉┉┉┉and┉┉┉┉┉┉┫ ╎           ┌───────────┐       ┌───────────┐       ┌──────────┐ 
+                           ╎  ┃  http client ┃ ╯  ╭╌ ⇆ ╌ ╌ │ homematic │ ╌ ⇆ ╌ │ homematic │ ╌ ⇆ ╌ │ physical │ 
+                           ╎  ┃              ┃ ╌╌ ╯  ╭ ← ╌ │  ccujack  │       │  daemon   │       │   lock   │ 
+                           ⇅  ┣┉┉┉┉┉and┉┉┉┉┉┉┫       ╎     └───────────┘       └───────────┘       └──────────┘ 
+                           ╎  ┃  mqtt client ┃╌ ← ╌  ╯     ┌────────────────┐
+                           ╎  ┃              ┃ ╌ ╌ ╌ → ╌ ╌ │ Club-Assistant │
+                           ╎  ┗━━━━━━━━━━━━━━┛             └────────────────┘
+                           ╎
+                           ╰ ╌ ╌ ╌ ╌ ╌ ⇄ ╌ ╌ ╌ ╌ ╮
+┌────────────┐              ┌──────────────────┐ ╎
+│ SSH client │ ╌ ╌ ╌ ⇆ ╌ ╌ ╌│ dooris "ssh-cli" │ ╯
+└────────────┘              └──────────────────┘
+```
+
+- Boxes indicate a discrete daemon or running piece of software. Those sometimes include subcomponents of that daemon for clarity.
+- Dotted connections indicate information flow while the arrows indicate the direction of that flow
+
 ## Configuration
 
 The final application can be configured either via CLI arguments or via environment variables.