docs(lookup): add example to lookup function and comment to configs file

Added an example and detailed parameters to the `findThreadMatches` function in the lookup file. Provided a comment in the configs file explaining the purpose and version of the exported Google Safe Browsing API endpoint.

src/configs.ts

@@ -1 +1,4 @@
+/**
+ * The base URL of the Google Safe Browsing API. The current version is v4.
+ */
 export const endpoint = 'https://safebrowsing.googleapis.com/v4'

src/lookup.ts

@@ -28,6 +28,26 @@ export type FindThreadMatchesResponse = {
 /**
  * Finds threat matches using Google Safe Browsing API.
  *
+ * @example
+ * ```ts
+ * const result = await findThreadMatches('apiKey', {
+ *   client: {
+ *     clientId: 'uniqueClientId',
+ *     clientVersion: '1.0.0',
+ *   },
+ *   threatInfo: {
+ *     threatTypes: ['MALWARE', 'SOCIAL_ENGINEERING'],
+ *     platformTypes: ['ALL_PLATFORMS'],
+ *     threatEntryTypes: ['URL'],
+ *     threatEntries: [
+ *       { url: 'http://malware.testing.google.test/testing/malware/' },
+ *     ],
+ *   },
+ * })
+ *
+ * const hasRisk = result.matches !== undefined && result.matches.length > 0
+ * ```
+ *
  * @param apiKey The API key for accessing the Google Safe Browsing API. You should follow the instruction to get the API key at https://developers.google.com/safe-browsing/v4/get-started.
  * @param request The request object containing the parameters for finding thread matches.
  *