add some comments

src/main.zig

@@ -19,5 +19,6 @@ pub fn main() !void {
     const args = try std.process.argsAlloc(allocator);
     defer std.process.argsFree(allocator, args);
 
+    // parse the args and handle command
     try command.handle_command(args);
 }

src/tools.zig

@@ -31,6 +31,7 @@ pub fn get_allocator() std.mem.Allocator {
     return allocator;
 }
 
+/// get zvm path segment
 pub fn get_zvm_path_segment(tmp_allocator: std.mem.Allocator, segment: []const u8) ![]u8 {
     return std.fs.path.join(
         tmp_allocator,

src/versions.zig

@@ -1,22 +1,31 @@
+//! For getting zig version info json from offical website
 const std = @import("std");
 const config = @import("config.zig");
 
 const uri = std.Uri.parse(config.download_manifest_url) catch unreachable;
 
 pub const VersionList = struct {
+    // this type will store
     const List = std.ArrayList([]const u8);
+
+    // store the version message
     lists: List,
     allocator: std.mem.Allocator,
 
+    /// init the VersionList
     pub fn init(allocator: std.mem.Allocator) !VersionList {
+        // create a http client
         var client = std.http.Client{ .allocator = allocator };
         defer client.deinit();
 
+        // we ceate a buffer to store the http response
         var buffer: [262144]u8 = undefined; // 256 * 1024 = 262kb
 
+        // try open a request
         var req = try client.open(.GET, uri, .{ .server_header_buffer = &buffer });
         defer req.deinit();
 
+        // send request and wait response
         try req.send();
         try req.wait();
 
@@ -26,6 +35,7 @@ pub const VersionList = struct {
 
         const len = try req.readAll(buffer[0..]);
 
+        // parse json
         const json = try std.json.parseFromSlice(std.json.Value, allocator, buffer[0..len], .{});
         defer json.deinit();
         const root = json.value;
@@ -47,10 +57,12 @@ pub const VersionList = struct {
         };
     }
 
+    // get the slice items
     pub fn slice(self: *VersionList) [][]const u8 {
         return self.lists.items;
     }
 
+    /// deinit will free memory
     pub fn deinit(self: *VersionList) void {
         defer self.lists.deinit();
         for (self.lists.items) |value| {