Write install instructions (README.md)

Makefile

@@ -1,4 +1,4 @@
-LISP ?= ecl
+LISP ?= sbcl
 SWANK ?= ${HOME}/.config/emacs/elpa/slime-20221206.26/swank-loader.lisp
 USE_SWANK ?= no
 
@@ -9,7 +9,7 @@ maps:
 	$(LISP) \
 		--load "res/maps/tmx→lisp.lisp"
 
-build:
+build: maps fonts
 	$(LISP) \
 		--eval '(ql:quickload :flora-search-aurora)' \
 		--eval '(asdf:make :flora-search-aurora)' \

README.md

@@ -0,0 +1,36 @@
+# Flora Search Aurora
+
+## Installation
+
+You can run the game through a pre-built binary, available under Releases of this repository.
+
+If you’d rather (or have to) run the game from source, you can set up the game like so:
+
+1. Install a Common Lisp implementation. I’d recommend [Steel Bank Common Lisp](http://www.sbcl.org/), which is robust and available on many *nixes under the package-name `sbcl`.
+2. Set up [Quicklisp](https://quicklisp.org/), which is a “package-manager” for Common Lisp libraries.
+3. Clone this repo into your Quicklisp projects path.
+4. Run or build the game with `make run` or `make build`.
+
+To do so, you can run the following commands, replacing `guix` with your package-manager of choice:
+
+```
+$ guix install sbcl
+$ wget https://beta.quicklisp.org/quicklisp.lisp
+$ sbcl --load quicklisp.lisp \
+	--eval '(quicklisp-quickstart:install :path "~/.local/share/quicklisp/)' \
+	--eval '(ql:add-to-init-file)'
+$ rm quicklisp.lisp
+$ cd ~/.local/share/quicklisp/local-projects/
+$ git clone https://notabug.org/jadedctrl/flora-search-aurora
+$ cd flora-search-aurora/
+$ make build
+$ ./flora-search-aurora
+```
+
+For development, so that you can connect to the game’s REPL with (i.e.) [SLIME](https://slime.common-lisp.dev/), you might want to run the game like so:
+
+`$ USE_SWANK=yes SWANK=… make run`
+
+… where SWANK is the path to SLIME’s `swank-loader.lisp` file, probably at `~/.config/emacs/elpa/slime-*/swank-loader.lisp`.
+
+The game has been tested with both [Embeddable Common Lisp](https://ecl.common-lisp.dev/) and SBCL. It runs perfectly on both, but building a binary isn’t working on ECL at the moment.