Update installation instructions

README.md

@@ -11,13 +11,23 @@ You can install a stable version of MetAcsl through [`opam`](https://opam.ocaml.
 
 If you want to compile it manually from the git repository, you need to have Frama-C installed,
 and to ensure that the MetAcsl branch you intend to work on is compatible with it
-(NB: the `master` branches from both repositories are supposed to stay synchronized).
+(NB: the `master` branches from both repositories are supposed to stay synchronized,
+ as well as any `stable/*` branch).
 
 Optional dependencies, needed for using the [deduction](#deduction) capabilities of MetAcsl include:
 - [Why3](https://why3.lri.fr) (only for checking the consistency of MetAcsl's deduction model)
 - [SWI Prolog](https://www.swi-prolog.org/)
 
-Then, run the usual `autoconf && ./configure && make && make install`
+Since version 0.4, MetAcsl uses [`dune`](https://dune.build/) as build system (following Frama-C's lead),
+so that you can install MetAcsl with the following commands:
+```
+dune build
+dune install
+```
+
+This will install MetAcsl in the same place as Frama-C.
+
+For convenience, you can still use `make && make install` to perform the same thing.
 
 ## Usage