docs: archive the frozen stage code as one compressed tarball

docs/history kept six stages with a full copy of the project under code/,
3.8 mb of sources duplicated from stage to stage and already superseded. store
them as docs/history/code-snapshots.tar.gz, 0.66 mb, and extract one in place
to read it. every stage's notes.md stays browsable, and the index says where the
code went and how to get it back.

the top-level README points at the archive too. its other two links into
docs/history, 21-micro and 35-bench, were notes that were never kept and do not
resolve; the index now records that.

1 files changed, 0 insertions, 22 deletions

diff --git a/docs/history/13-gap-fixes/code/tests/basics.zc b/docs/history/13-gap-fixes/code/tests/basics.zc
deleted file mode 100644
index c1f1faf..0000000
--- a/docs/history/13-gap-fixes/code/tests/basics.zc
+++ /dev/null
@@ -1,22 +0,0 @@
-let table[10];
-let greeting = "hey";
-const N = 10, BIG = 0x100 * 2;
-fn fib(n) { if (n < 2) return n; return fib(n - 1) + fib(n - 2); }
-fn twice(f, x) { return f(f(x)); }
-fn inc(x) { return x + 1; }
-fn main()
-{
-	let i, s = 0, a[5];
-	for (i = 0; i < N; i++) table[i] = i * i;
-	for (let j = 0; j < N; j++) s += table[j];
-	putn(s); putc(' '); putn(fib(15)); putc(' '); putn(twice(inc, 40)); putc(' '); putn(BIG); putc(10);
-	puts(greeting); putc(' '); putn('A'); putc(' '); putn(-17 / 5); putc(' '); putn(-17 % 5); putc(' '); putn(1 << 10); putc(' '); putn(-64 >> 3); putc(10);
-	i = 0; while (1) { i++; if (i == 3) continue; if (i > 6) break; putn(i); } putc(10);
-	a[0] = 5; a[1] = a[0]++; a[2] = ++a[0]; putn(a[0]); putn(a[1]); putn(a[2]); putc(10);
-	let b = { let t = 3; t * t };
-	putn(b); putc(' '); putn(3 > 2 && 2 > 1); putn(0 || 0); putn(!5); putn(~0); putn(5 != 5); putn(4 >= 4); putc(10);
-	let x = asm { 2 3 + };
-	putn(x); putc(10);
-	asm { 'o' . 'k' . 10 . }
-	return 0;
-}