Add anki21 format and fix multi import bug

Cargo.toml

@@ -10,7 +10,7 @@ rand = "0.10.2"
 dirs = "6.0.0"
 serde = { version = "1.0.229", features = ["derive"] }
 serde_json = "1.0.151"
-rhai = "1.25.1"
+rhai = { version = "1.25.1", features = ["sync"] }
 chrono = "0.4.45"
 rusqlite = { version = "0.40.2", features = ["chrono", "bundled"] }
 reqwest = { version = "0.13.4", features = ["json", "stream", "multipart"] }
@@ -23,6 +23,7 @@ zip = "8.6.0"
 rfd = "0.17.2"
 mimalloc = "0.1.52"
 hashbrown = "0.17.1"
+rayon = "1.12.0"
 
 [profile.super-release]
 inherits = "release"