improve the readme (#25)

Author: danieleades

README.md

@@ -1,3 +1,12 @@
 # Arithmetic Coding
 
-A symbolic arithmetic coding library
+[![Latest Docs](https://docs.rs/arithmetic-coding/badge.svg)](https://docs.rs/arithmetic-coding/)
+![Continuous integration](https://github.com/danieleades/arithmetic-coding/workflows/Continuous%20integration/badge.svg)
+[![codecov](https://codecov.io/gh/danieleades/arithmetic-coding/branch/main/graph/badge.svg?token=1qITX2tR0J)](https://codecov.io/gh/danieleades/arithmetic-coding)
+
+
+A symbolic [arithmetic coding](https://en.wikipedia.org/wiki/Arithmetic_coding) library.
+
+Extending this library is as simple as implementing the `Model` trait for your own type, and then plugging it in the provided `Encoder`/`Decoder`. Supports both fixed-length and variable-length encoding, as well as both adaptive and non-adaptive models.
+
+Take a look at the  [API docs](https://docs.rs/arithmetic-coding/) or the [examples](https://github.com/danieleades/arithmetic-coding/tree/main/examples).

arithmetic-coding-core/src/fixed_length.rs

@@ -135,7 +135,7 @@ pub struct Wrapper<M>
 where
     M: Model,
 {
-    inner_model: M,
+    model: M,
     remaining: usize,
 }
 
@@ -146,10 +146,7 @@ where
     /// Construct a new wrapper from a [`fixed_length::Model`](Model)
     pub fn new(model: M) -> Self {
         let remaining = model.length();
-        Self {
-            inner_model: model,
-            remaining,
-        }
+        Self { model, remaining }
     }
 }
 
@@ -168,9 +165,7 @@ where
         if self.remaining > 0 {
             if let Some(s) = symbol {
                 // Expected a symbol and got one. return the probability.
-                self.inner_model
-                    .probability(s)
-                    .map_err(Self::ValueError::Value)
+                self.model.probability(s).map_err(Self::ValueError::Value)
             } else {
                 // We are expecting more symbols, but got an EOF
                 Err(Self::ValueError::UnexpectedEof)
@@ -185,24 +180,24 @@ where
     }
 
     fn max_denominator(&self) -> Self::B {
-        self.inner_model.max_denominator()
+        self.model.max_denominator()
     }
 
     fn symbol(&self, value: Self::B) -> Option<Self::Symbol> {
         if self.remaining > 0 {
-            Some(self.inner_model.symbol(value))
+            Some(self.model.symbol(value))
         } else {
             None
         }
     }
 
     fn denominator(&self) -> Self::B {
-        self.inner_model.denominator()
+        self.model.denominator()
     }
 
     fn update(&mut self, symbol: Option<&Self::Symbol>) {
         if let Some(s) = symbol {
-            self.inner_model.update(s);
+            self.model.update(s);
             self.remaining -= 1;
         }
     }