Fix some links

Author: GuillaumeGomez

src/libcore/num/flt2dec/strategy/dragon.rs

@@ -9,9 +9,9 @@
 // except according to those terms.
 
 /*!
-Almost direct (but slightly optimized) Rust translation of Figure 3 of [1].
+Almost direct (but slightly optimized) Rust translation of Figure 3 of \[1\].
 
-[1] Burger, R. G. and Dybvig, R. K. 1996. Printing floating-point numbers
+\[1\] Burger, R. G. and Dybvig, R. K. 1996. Printing floating-point numbers
     quickly and accurately. SIGPLAN Not. 31, 5 (May. 1996), 108-116.
 */
 

src/libcore/num/flt2dec/strategy/grisu.rs

@@ -9,10 +9,10 @@
 // except according to those terms.
 
 /*!
-Rust adaptation of Grisu3 algorithm described in [1]. It uses about
+Rust adaptation of Grisu3 algorithm described in \[1\]. It uses about
 1KB of precomputed table, and in turn, it's very quick for most inputs.
 
-[1] Florian Loitsch. 2010. Printing floating-point numbers quickly and
+\[1\] Florian Loitsch. 2010. Printing floating-point numbers quickly and
     accurately with integers. SIGPLAN Not. 45, 6 (June 2010), 233-243.
 */