docs(api): document hashDigest etc. (#7405)

Author: chenxsan

src/content/api/loaders.mdx

@@ -389,6 +389,38 @@ module.exports = function (source) {
 };
 ```
 
+### this.hashDigest
+
+`string`
+
+<Badge text="5.95.0+" />
+
+The encoding to use when generating the hash. See [output.hashDigest](/configuration/output/#outputhashdigest).
+
+### this.hashDigestLength
+
+`number`
+
+<Badge text="5.95.0+" />
+
+The prefix length of the hash digest to use. See [output.hashDigestLength](/configuration/output/#outputhashdigestlength).
+
+### this.hashFunction
+
+`string` `function`
+
+<Badge text="5.95.0+" />
+
+The hashing algorithm to use. See [output.hashFunction](/configuration/output/#outputhashfunction).
+
+### this.hashSalt
+
+`string`
+
+<Badge text="5.95.0+" />
+
+An optional salt to update the hash via Node.JS' [`hash.update`](https://nodejs.org/api/crypto.html#crypto_hash_update_data_inputencoding). See [output.hashSalt](/configuration/output/#outputhashsalt).
+
 ### this.importModule
 
 <Badge text="5.32.0+" />