fix: update dependencies in generated README (#82)

Author: booniepepper

template/README-github.md

@@ -17,7 +17,7 @@
 
 **TODO: adapt this section**
 
-- `bash`, `curl`, `tar`: generic POSIX utilities.
+- `bash`, `curl`, `tar`, and [POSIX utilities](https://pubs.opengroup.org/onlinepubs/9699919799/idx/utilities.html).
 - `SOME_ENV_VAR`: set this environment variable in your shell config to load the correct version of tool x.
 
 # Install

template/README-gitlab.md

@@ -17,7 +17,7 @@
 
 **TODO: adapt this section**
 
-- `bash`, `curl`, `tar`: generic POSIX utilities.
+- `bash`, `curl`, `tar`, and [POSIX utilities](https://pubs.opengroup.org/onlinepubs/9699919799/idx/utilities.html).
 - `SOME_ENV_VAR`: set this environment variable in your shell config to load the correct version of tool x.
 
 # Install