Update compile and install instructions

README.md

@@ -52,10 +52,58 @@ learning exercise!
 
 ## How
 
+### Compiling
+
 This project is written in Rust, so you'll need a rust compiler to build it.
 [Rustup]() comes highly recommended. Deltachat is also written in Rust and it
 needs the `nightly` version, so follow the instructions for that.
 
+Once you have a working rust compiler, just:
+
+```
+$ cargo build --release
+```
+
+to get a `telepathy-padfoot binary.
+
+
+### Cross-compiling amd64 -> i386
+
+If you need a 32-bit binary and you're on an am64 bit system, this seems to
+work, as long as you have 32-bit versions of `libdbus-1` and `libssl` installed.
+
+On Debian, the full sequence looks like:
+
+```
+$ dpkg --print-architecture
+amd64
+# dpkg --add-architecture i386
+$ dpkg --print-foreign-architectures
+i386
+# apt update
+# apt install libdbus-1-dev:i386 libssl-dev:i386
+$ rustup target install i686-unknown-linux-gnu
+$ PKG_CONFIG_ALLOW_CROSS=1 cargo build --target=i686-unknown-linux-gnu --release
+```
+
+This creates a 32-bit executable at `target/i686-unknown-linux-gnu/release/telepathy-padfoot`
+
+I don't have a 32-bit machine to test this on, but happy to take fixes for it.
+
+### Installing
+
+There is a `share/` directory in this project that contains a bunch of files.
+They should be placed into `/usr/share`, following the same layout. Then put
+the binary into `/usr/lib/telepathy/telepathy-padfoot`.
+
+I should probably put this into the makefile.
+
+
+
+
+### Autogenerated telepathy DBUS bindings
+
+
 It makes use of the `dbus-codegen-rust` crate to convert the
 [telepathy interface specs](https://github.com/TelepathyIM/telepathy-spec) into
 the executable code in `src/telepathy`. This is checked in, but can be