chore: update README

Author: typesafe

README.md

@@ -0,0 +1,48 @@
+# Cuid2
+
+Secure, collision-resistant ids optimized for horizontal scaling and performance. Next generation UUIDs.
+
+Need unique ids in your app? Forget UUIDs and GUIDs which often collide in large apps. Use Cuid2, instead.
+
+This is a port of the JavaScript library [@paralleldrive/cuid2](https://github.com/paralleldrive/cuid2), rewritten in Zig. For more detailed information about Cuid2, please refer to the [original documentation](https://github.com/paralleldrive/cuid2/blob/main/README.md).
+
+## Usage
+
+`cuid2-zig` requires no memory allocations and is very simple to use. Simply specify the identifier length (a `comptime` value in range `[2,32]`),
+initialize it and generate ids:
+
+```zig
+const length = 24; // comptime
+
+var generator = Cuid2(length).init(.{});
+
+// `next` returns a fixed-size array of 24 base36 bytes
+const id = generator.next();
+```
+
+You can also specify a custom random function in the `init` options:
+
+````zig
+const std = @import("std");
+
+pub const cuid2 = @import("cuid2");
+
+pub fn main() !void {
+    var generator = cuid2.Cuid2(24).init(.{ .random = customRandom });
+
+    std.debug.print("generated id '{s}'\n", .{generator.next()});
+}
+
+fn customRandom() f64 {
+    // or any other implementation, `std.rand.DefaultCsprng`, ...
+    return std.crypto.random.float(f64);
+}
+````
+
+The random function must return a `f64` value in range `[0,1)`.  The default implementation uses `std.rand.DefaultPrng` with a `std.time.microTimestamp()` seed.
+
+## Importing the library
+
+TODO
+
+

src/cuid2.zig

@@ -18,6 +18,9 @@ const Options = struct {
 };
 
 /// Create a cuid2 generator.
+///
+/// Parameters:
+/// - `length`: a comptime value in range [2, 32] to specify the length of the generated identifiers.s
 pub fn Cuid2(comptime length: u8) type {
     if (length < MinIdLength or length > MaxIdLength) {
         @compileError("Invalid idLength. Cuid2 id length must be in the range [2,32].");
@@ -41,6 +44,7 @@ pub fn Cuid2(comptime length: u8) type {
             };
         }
 
+        /// Generates a cuid2 identifier.
         pub fn next(self: *Self) [length]u8 {
 
             // u64 values result in max 13 base36 chars