Update documentation with detailed descriptions for clarity

Added comprehensive descriptions to documentation files across IdentityServer, BFF, AccessTokenManagement, and IdentityModel sections. These updates improve clarity by providing detailed overviews, usage guides, and implementation instructions for various features and workflows.

Author: khalidabuhakmeh

src/components/duende-og-image.tsx

@@ -31,8 +31,8 @@ export async function duendeOpenGraphImage({
             "flex flex-col justify-end justify-items-start w-full h-full p-20",
           )}
         >
-          <h1 style={twj("text-[100px] text-bold text-white")}>{title}</h1>
-          <div style={twj("text-2xl text-bold mb-3 text-white")}>
+          <h1 style={twj("text-[75px] text-bold text-white")}>{title}</h1>
+          <div style={twj("text-3xl text-bold mb-3 text-white")}>
             {description}
           </div>
         </div>