chore: fix 404 status URL (#892)

Signed-off-by: wangjingcun <wangjingcun@aliyun.com>

ec/README.md

@@ -134,8 +134,8 @@ assert!(new_a.is_in_correct_subgroup_assuming_on_curve());
 Besides the foregoing abstract interfaces for elliptic curve groups, `ark-ec` also provides
 the following concrete instantiations of common elliptic curve models:
 
-* [*Short Weierstrass*](https://github.com/arkworks-rs/algebra/blob/master/ec/src/models/short_weierstrass.rs) curves. The `AffineRepr` in this case is in typical Short Weierstrass point representation, and the `CurveGroup` is using points in [Jacobian Coordinates](https://en.wikibooks.org/wiki/Cryptography/Prime_Curve/Jacobian_Coordinates).
-* [*Twisted Edwards*](https://github.com/arkworks-rs/algebra/blob/master/ec/src/models/twisted_edwards.rs) curves. The `AffineRepr` in this case is in standard Twisted Edwards curve representation, whereas the `CurveGroup` uses points in [Extended Twisted Edwards Coordinates](https://eprint.iacr.org/2008/522.pdf).
+* [*Short Weierstrass*](https://github.com/arkworks-rs/algebra/blob/master/ec/src/models/short_weierstrass/mod.rs) curves. The `AffineRepr` in this case is in typical Short Weierstrass point representation, and the `CurveGroup` is using points in [Jacobian Coordinates](https://en.wikibooks.org/wiki/Cryptography/Prime_Curve/Jacobian_Coordinates).
+* [*Twisted Edwards*](https://github.com/arkworks-rs/algebra/blob/master/ec/src/models/twisted_edwards/mod.rs) curves. The `AffineRepr` in this case is in standard Twisted Edwards curve representation, whereas the `CurveGroup` uses points in [Extended Twisted Edwards Coordinates](https://eprint.iacr.org/2008/522.pdf).
 
 ### Pairings