docs(readme): update README.th.md translation for thai native

[BadPROGRMMR]

Update thai translation in readme for readability and native-friendly

Issue for this PR

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

the current translation for README.th.md is alright but very hard for thai native people to read

How did you verify your code works?

i am thai native and i can verify that this change is more readable for thai native

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

Hey! Your PR title Update README.th.md for clarity and native-friendly doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍

[BadPROGRMMR]

the terms "The open source AI coding agent" can be directly translate to "AI โค้ดดิ้งเอเจนต์แบบโอเพนซอร์ส" in thai if prefer a less formal and more native-friendly approach

[BadPROGRMMR]

either the original contributor or my translation is okay but we usually use "วิธีการติดตั้ง" for software and "การติดตั้ง" for hardware

[BadPROGRMMR]

the add "(ใช้คำสั่งเดียว)" is for clarity for thai native that don't understand the term "YOLO"

[BadPROGRMMR]

While the word "branch" does translate to "สาขา" but thai native usually use "สาขา" when they refer to a franchise branch like a mcdonald branch so the in this context the "dev branch" is refer to the latest developing branch which can be translate to "เวอชันพัฒนาล่าสุด/เวอชันล่าสุดสำหรับนักพัฒนา" นักพัฒนา is thai word for developer

[BadPROGRMMR]

add more clarity for thai native the word "หน้ารุ่น" does feel a bit weird since the word "รุ่น" usually use to refer an object like "Iphone รุ่น 15/16/17" but for some thing like software for example for ios we usually use "ios เวอชัน 21/22/23"

[BadPROGRMMR]

both "ชุมชน" and "คอมมูนิตี้" is fine for "Community" translation but the word "คอมมูนิตี้" can also be shorten to "คอมมู" for a less formal tone and native-friendly