Fix typo (#206)
diff --git a/src/lib.rs b/src/lib.rs
index 2cb196a..b8568ad 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -159,7 +159,7 @@
//! - `is_empty`: `true` if no flags are currently stored
//! - `is_all`: `true` if currently set flags exactly equal all defined flags
//! - `intersects`: `true` if there are flags common to both `self` and `other`
-//! - `contains`: `true` all of the flags in `other` are contained within `self`
+//! - `contains`: `true` if all of the flags in `other` are contained within `self`
//! - `insert`: inserts the specified flags in-place
//! - `remove`: removes the specified flags in-place
//! - `toggle`: the specified flags will be inserted if not present, and removed
