update dead links in README, update version and syntax of markdown

README.md

@@ -1,12 +1,8 @@
 # Conda Recipes for RMG-Py dependencies
 
-Example recipes for the new conda build system.  Use
+Example recipes for the conda build system.
+Run `conda build <recipe directory>`.
 
-    conda build <recipe directory>
-
-You have to use conda >= 1.7
-[conda](https://github.com/continuumio/conda).
-
-See http://docs.continuum.io/conda/build.html for information on how to make a recipe,
-or just look at the examples here.
+You have to use `conda >=  23.1.0` - see the [installation instructions](https://docs.anaconda.com/free/anaconda/install/).
 
+See [the `conda` documentation](https://docs.conda.io/projects/conda-build/en/latest/user-guide/tutorials/build-pkgs.html) for information on how to make a recipe or just look at the examples here.