Parallelize fetching

Cargo.toml

@@ -37,6 +37,7 @@ tokio = { version = "1.32.0", features = ["rt-multi-thread", "macros", "fs", "ti
 futures = "0.3.28"
 html2md = "0.2.14"
 readability = "0.2.0"
+parking_lot = "0.12.1"
 async-trait = "0.1.73"
 
 [dev-dependencies]

README.md

@@ -216,7 +216,7 @@ placed at `~/.config/bogrep` in your home directory:
 ``` json
 {
     "cache_mode": "text",
-    "max_concurrent_requests": 100,
+    "max_parallel_requests": 100,
     "request_timeout": 60000,
     "request_throttling": 3000,
     "max_idle_connections_per_host": 10,
@@ -227,7 +227,7 @@ placed at `~/.config/bogrep` in your home directory:
 where `request_throttling` is the waiting time between requests for the same
 host in milliseconds.
 
-Too speed up fetching, set `max_concurrent_requests` to e.g. 1000. The maximum
+Too speed up fetching, set `max_parallel_requests` to e.g. 1000. The maximum
 number of available sockets depends on your operating system. Run `ulimit -n` to
 show the maximum number of open sockets allowed on your system.
 

src/bookmarks/mod.rs

@@ -10,6 +10,13 @@ use std::{
 };
 pub use target_bookmarks::{TargetBookmark, TargetBookmarks};
 
+/// The action to be performed on the bookmark.
+#[derive(Debug, Serialize, Deserialize, PartialEq, Eq, Clone)]
+pub enum Action {
+    Add,
+    Remove,
+}
+
 /// The type used to identify a source.
 #[derive(Debug, Clone, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
 pub enum SourceType {