Add some known issues to the README.

README.md

@@ -11,7 +11,7 @@ Contains code from [flare](https://gitlab.com/schmiddi-on-mobile/flare) by [Schm
 1. Create a new Pidgin account. Enter your Signal account UUID as username. In case you do not know your UUID, just enter anything. The plug-in will tell you what to use.
 2. Enable the connection. A window with the QR-code should pop-up. Scan it with your master device. Wait for the window to close.
 
-Note: bitlbee users will receive the login QR-code in form of a URI from a system contact "Logon QR Code". You may need to allow unsolicited messages from unknown contacts in your client. The URI can be converted using any tools like local [`qrencode`](https://www.shellhacks.com/qr-code-generator-windows-linux-macos/) or [online services](https://www.the-qrcode-generator.com/) (use at your own risk).
+Note: bitlbee users will receive the login QR-code in form of a URI from a system contact "Logon QR Code". You may need to allow unsolicited messages from unknown contacts in your client. The URI can be converted using any tool like a local [`qrencode`](https://www.shellhacks.com/qr-code-generator-windows-linux-macos/) or [online services](https://www.the-qrcode-generator.com/) (use at your own risk).
 
 ## Features
 
@@ -56,7 +56,9 @@ These lists are not exhaustive.
 * Handling errors when sending messages is barely tested.
 * Attachments end up in the conversation of the sender, not the destination (especially confusing when a group chat is involved).
 * Failing to send an attachment may bring down the entire application.
-* Some message features such as displaying edits do not work for sync messages or do not work at all.
+* Some message features such as displaying edits do not work reliably, especially on sync messages (send from same account, but other device).
+* Sync messages are unreliable, especially in regard to attachments (attachments sent from another device may not be received by the plug-in).
+* Some times, the error message `"config_store Err Db(Io(Custom { kind: Other, error: "could not acquire lock on \"…/db\": Os { code: 11, kind: WouldBlock, message: \"Resource temporarily unavailable\" }" }))"` is shown. Just wait a few seconds and try again. Usually, it wors after a couple of retries.
 
 ## Building