Autoconf 2.70 shipped WASI support (#193)

README.md

@@ -45,11 +45,11 @@ is not necessary if `WASI_SDK_PATH` is `/opt/wasi-sdk`.
 
 ## Notes for Autoconf
 
-Upstream autoconf now
+[Autoconf](https://www.gnu.org/software/autoconf/autoconf.html) 2.70 now
-[recognizes WASI](http://lists.gnu.org/archive/html/config-patches/2019-04/msg00001.html).
+[recognizes WASI](https://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=blob;f=build-aux/config.sub;h=19c9553b1825cafb182115513bc628e0ee801bd0;hb=97fbc5c184acc6fa591ad094eae86917f03459fa#l1723).
 
 For convenience when building packages that aren't yet updated, updated
-config.sub and config.guess files are installed at share/misc/config.\*
+config.sub and config.guess files are installed at `share/misc/config.*`
 in the install directory.
 
 ## Notable Limitations