Add docs for blossom, add nip 86 and 98 support

docs/util/nip98.md

@@ -0,0 +1,42 @@
+# NIP-98 HTTP Auth
+
+Implementation of NIP-98 HTTP Authentication for authenticating HTTP requests with Nostr events.
+
+## Functions
+
+```typescript
+// Creates an HTTP auth event for authenticating requests
+export declare const makeHttpAuth: (url: string, method?: string, body?: string) => Promise<Event>
+
+// Creates Authorization header from signed HTTP auth event
+export declare const makeHttpAuthHeader: (event: SignedEvent) => string
+```
+
+## Example
+
+```typescript
+import { makeHttpAuth, makeHttpAuthHeader } from '@welshman/util'
+
+const url = "https://api.example.com/upload"
+const method = "POST"
+const body = {data: "example"}
+
+// Create HTTP auth event
+const authEvent = await makeHttpAuth(url, method, JSON.stringify(body))
+
+// Sign the auth event
+const signedEvent = await signer.signEvent(authEvent)
+
+// Create Authorization header
+const authHeader = makeHttpAuthHeader(signedEvent)
+
+// Use in fetch request
+const response = await fetch(url, {
+  body,
+  method,
+  headers: {
+    "Authorization": authHeader,
+    "Content-Type": "application/json"
+  },
+})
+```