feat: update readme, add pinentry

README.md

@@ -35,9 +35,28 @@ sshp11 root@example.com
 
 ## Configuration
 
+### Turn on retired slots
+
 Default retired slots are disabled, turn on:
 
 ```shell
 export ENABLE_RETIRED=1
 ```
 
+## Pin entry
+
+Default pin entry command:
+
+```
+/usr/local/MacGPG2/libexec/pinentry-mac.app/Contents/MacOS/pinentry-mac
+```
+
+Set pin entry command by env:
+
+```shell
+export PIN_ENTRY_CMD=pin-entry-command
+```
+
+or edit file `~/.pinentry.cmd`,
+
+if no pin entry found, will use `pinentry`.