new init-exe template

- removed an unnecessary (and confusing) `anyerror` fronm the function
  signature of `main`
- replaced the call to std.log with two prints: one to stderr and one to
  stdout
- replaced the test code with a better example

lib/init-exe/src/main.zig

@@ -1,11 +1,22 @@
 const std = @import("std");
 
-pub fn main() anyerror!void {
-    // Note that info level log messages are by default printed only in Debug
-    // and ReleaseSafe build modes.
-    std.log.info("All your codebase are belong to us.", .{});
+pub fn main() !void {
+    // Prints to stderr
+    std.debug.print("All your {s} are belong to us.\n", .{"codebase"});
+
+    // Prints to stdout
+    const unbuffered_out = std.io.getStdOut().writer();
+    const out = std.io.bufferedWriter(unbuffered_out).writer();
+    try out.print("Run `zig build test` to run the tests.\n", .{});
+
+    // Stdout is for the actual output of your application, for example if you
+    // are implementing gzip, then only the compressed bytes should be sent to
+    // stdout, not any debugging messages!
 }
 
-test "basic test" {
-    try std.testing.expectEqual(10, 3 + 7);
+test "simple test" {
+    var list = std.ArrayList(i32).init(std.testing.allocator);
+    defer list.deinit(); // try commenting this out and see if zig detects the memory leak!
+    try list.append(42);
+    try std.testing.expectEqual(list.pop(), 42);
 }