Revert "Basic architecture diagram for a potential deadlink checker"

This reverts commit 8ca4861a23.

src/deadlinks/architecture.mermaid

@@ -1,21 +0,0 @@
-flowchart LR
-    subgraph DeadLinks
-        URLs["`[]URL{
-        - URLString
-        - LastChecked
-        - Status
-        - DestURLs
-        - Pinned
-        }`"]
-        style URLs text-align:left
-
-        Cleaner -->|"periodically delete where\nnot linked to and not pinned"| URLs
-
-        CheckerWorker -->|getNext| Queue
-        Queue -->|iterate over stale| URLs
-        CheckerWorker -->|upsert| URLs
-    end
-
-    User -->|upsert pinned| URLs
-    User -->|notify pinned| Queue
-    User -->|query by state| URLs