Added brief modules documentation (#21)

src/bcp47.rs

@@ -14,6 +14,8 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+//! A module for matching locales in the [BCP 47](https://www.ietf.org/rfc/bcp/bcp47.html) format.
+
 use language_tags::LanguageTag;
 
 /// Finds the best matching locale from a list of available locales based on a list of user locales.  

src/lib.rs

@@ -17,8 +17,8 @@
 //! A small library for selecting the best match for user's preferred locales from available locales.
 //!
 //! The library consists of two modules:
-//! * `bcp47` - for matching locales in the [BCP 47](https://www.ietf.org/rfc/bcp/bcp47.html) format
-//! * `posix` - for matching locales in the [POSIX](https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap08.html) format
+//! * [`bcp47`] — for matching locales in the [BCP 47](https://www.ietf.org/rfc/bcp/bcp47.html) format.
+//! * [`posix`] — for matching locales in the [POSIX](https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap08.html) format.
 //!
 //! Both modules provide the `best_matching_locale` function.
 //! 

src/posix.rs

@@ -14,6 +14,8 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+//! A module for matching locales in the [POSIX](https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap08.html) format.
+
 /// Finds the best matching locale from a list of available locales based on a list of user locales.  
 /// The function expects locales to be valid POSIX locales according to
 /// [The Open Group Base Specifications Issue 8 - 8. Environment Variables](https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/V1_chap08.html),