Revisit intro to Build/Oracles/Witnet

[guidiaz]

Describe the feature or improvement 描述新特性或改进

Intro, branding and description of Witnet is outdated.

Optional: Affected page(s) or section(s) 受影响的页面

Build / Oracles

Optional: Why is this feature or improvement important? 为什么需要这个新特性或改进？

No response

Optional: Implementation ideas 如何实现

No response

Optional: Additional context 其他上下文信息

No response

Contribution Confirmation

• I'd be willing to contribute this feature myself within 2 months. 我将在两个月内自己实现这个feature