Implement tab completion for ~/ (#164)

* Implement tab completion for ~/

Fixes #87.

* Fix clippy

Author: certik

crates/shell/src/completion.rs

@@ -62,6 +62,9 @@ fn complete_filenames(_is_start: bool, word: &str, matches: &mut Vec<Pair>) {
     // Determine the full directory path to search
     let search_dir = if dir_path.starts_with('/') {
         dir_path.to_string()
+    } else if let Some(stripped) = dir_path.strip_prefix('~') {
+        let home_dir = dirs::home_dir().unwrap();
+        format!("{}{}", home_dir.display(), stripped)
     } else {
         format!("./{}", dir_path)
     };