[docs] Experimental PoC for compiling with jsCoq SDK.

Based on the Docker solution, depends on `jscoq:sdk`.

examples/sdk-demo/Makefile

+
+REPO = https://github.com/coq-community/coqoban
+WORKDIR = workdir
+
+PATH := $(PWD)/bin:$(PATH)
+export PATH
+
+build: $(WORKDIR)
+	# Use current workspace, not jsCoq's
+	dune build --root .
+
+$(WORKDIR):
+	git clone --recursive --depth=1 $(REPO) $@
+
+clean:
+	dune clean --root .

examples/sdk-demo/bin/coqc

+#!/usr/bin/env node
+
+const child_process = require('child_process');
+
+const ME = 'jscoq',
+      DOCKER_IMAGE = `${ME}:sdk`;
+
+function mounts() {
+    var cwd = process.cwd(),
+        mnt = cwd.match(/[/][^/]+/)[0];
+
+    if (!mnt)
+        console.warn(`${ME}: cannot detect working directory root for '${cwd}';\n` +
+                     `       this will probably not work.`)
+
+    return (mnt ? [mnt] : []).map(d => `-v${d}:${d}`);
+}
+
+function run(args) {
+    var cmd = 'docker', args = [
+        'run', ...mounts(), `-w${process.cwd()}`, '--rm',
+        DOCKER_IMAGE, 'coqc', ...args
+    ];
+    var rc = child_process.spawnSync(cmd, args, {stdio: 'inherit'});
+
+    if (rc.error) {
+        console.log(`${ME}: failed to run Docker; ${rc.error}\n` +
+                    `  (${cmd} ${args.join(' ')})`);
+        process.exit(1);
+    }
+    if (rc.status) process.exit(rc.status);
+    if (rc.signal) { console.log('Killed'); process.exit(1); }
+}
+
+run(process.argv.slice(2));
\ No newline at end of file

examples/sdk-demo/dune

+
+(rule
+ (targets coq-pkgs)
+ (deps
+  (package coq-coqoban))
+ (action
+  (run npx %{env:pkgtool=jscoq} build workdir --top Coqoban
+       --package coq-pkgs/coqoban.coq-pkg)))
+
+(dirs workdir)

examples/sdk-demo/dune-project

+(lang dune 2.5)
+(using coq 0.2)

examples/sdk-demo/dune-workspace

+(lang dune 2.4)
+