feat: add open graph meta tags for social sharing

[ninja-silence]

<meta property="og:locale" content="en_US">
<meta property="og:title" content="All | Monad Improvement Proposals">
<meta property="og:description" content="Monad Improvement Proposals (MIPs) describe standards for the Monad platform, such as core protocol specifications.">
<meta property="og:url" content="https://mips.monad.xyz">
<meta property="og:site_name" content="Monad Improvement Proposals">
<meta property="og:type" content="website">
<meta property="og:image" content="https://mips.monad.xyz/assets/og-image.png">
<meta name="twitter:description" content="Monad Improvement Proposals (MIPs) describe standards for the Monad platform, such as core protocol specifications.">
<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:image" content="https://mips.monad.xyz/assets/og-image.png">
<meta name="twitter:site" content="@">

[QEDK]

Superseded by #69