feat(content): routing to provided .blog paths

This is a starting point to dynamically loading `markdown` files as blog
entries. With this change the *doc/about.md* and *doc/blog.md* files
are no longer builded into the executable and instead read from the
filesystem during runtime (along with the new test file *doc/test.md*).

build.zig

@@ -26,18 +26,6 @@ pub fn build(b: *std.Build) void {
             .imports = &.{
                 .{ .name = "zterm", .module = zterm.module("zterm") },
                 .{ .name = "zlog", .module = zlog.module("zlog") },
-                .{
-                    .name = "about",
-                    .module = b.createModule(.{
-                        .root_source_file = b.path("doc/about.md"),
-                    }),
-                },
-                .{
-                    .name = "blog",
-                    .module = b.createModule(.{
-                        .root_source_file = b.path("doc/blog.md"),
-                    }),
-                },
             },
         }),
     });