Update: Add MIC specification for primary exchange (#91)

This PR updates this param text to align with our documentation on the website.

src/main/kotlin/io/polygon/kotlin/sdk/rest/reference/Tickers.kt

@@ -83,8 +83,7 @@ data class SupportedTickersParameters(
  val market: String? = null,
 
  /**
- * Specify the primary exchange of the asset in the ISO code format.
- * Find more information about the ISO codes at the ISO org website.
+ * Specify the asset's primary exchange Market Identifier Code (MIC) according to ISO 10383.
  * Defaults to empty string which queries all exchanges.
  */
  val exchange: String? = null,
@@ -167,4 +166,4 @@ data class TickerDTO(
  @SerialName("share_class_figi") val shareClassFigi: String? = null,
  val ticker: String? = null,
  val type: String? = null
-)
+)