README.md: elaborate

* Add basic usage instructions
* Explain how to run examples
* Add link to new example (added in #24)

Author: mlugg

README.md

@@ -1,8 +1,49 @@
 # Translate-C
 
-A Zig package for translating C code into Zig code intended to replace `@cImport` and `zig translate-c`.
+A Zig package for translating C code into Zig code, intended to replace `@cImport` and `zig translate-c`.
 
-## Usage examples
+## Usage
+
+Add `translate-c` to your `build.zig.zon` with this command:
+
+```sh-session
+$ zig fetch --save git+https://github.com/ziglang/translate-c
+info: resolved to commit 1aa9ec052415feeaa0494190ae35a94849a24399
+```
+
+Then, within your `build.zig`, write something like this:
+
+```zig
+// An abstraction to make using translate-c as simple as possible.
+const Translator = @import("translate_c").Translator;
+
+// You *can* pass `target` and/or `optimize` in the options struct here, but it's typically
+// not necessary. You usually want to build for the host target, which is the default.
+const translate_c = b.dependency("translate_c", .{});
+
+const t: Translator = .init(translate_c, .{
+    .c_source_file = b.path("to_translate.h"),
+    .target = target,
+    .optimize = optimize,
+});
+// If you want, you can now call methods on `Translator` to add include paths (etc).
+
+// Depend on the translated C code as a Zig module.
+some_module.addImport("translated", t.mod);
+// ...or, if you want to, just use the output file directly.
+const translated_to_zig: LazyPath = t.output_file;
+```
+
+For a more complete usage, take a look at the [Examples](#examples).
+
+## Examples
+
+This repository contains a few examples in the `examples/` directory. You can test that all of the examples
+work by running `zig build all` in that directory.
+
+Within a specific example's directory, run `zig build test` to test that example. Most also have a step
+called `run` or similar which you can use to run the compiled program without hiding stdout.
 
 - [import header](examples/import_header/build.zig)
 - [compile c](examples/compile_c/build.zig)
+- [use static library](examples/use_static_lib/build.zig)