Fix credits link in highcharter helper

Change-Id: Id6eb586463ac14b48f76c7f1dd437bb3f6915358
diff --git a/R/highcharter-helper.R b/R/highcharter-helper.R
index 6601655..a78f57c 100644
--- a/R/highcharter-helper.R
+++ b/R/highcharter-helper.R
@@ -76,8 +76,8 @@
         click = JS("function() { window.open(this.click, 'korap'); }")
       )))) %>%
     hc_credits(enabled = TRUE,
-               text = "KorAP R Client Pakckage",
-               href = "//github.com/KorAP/RKorAPClient/") %>%
+               text = "KorAP R Client Package",
+               href = "https://github.com/KorAP/RKorAPClient/") %>%
     hc_exporting(enabled = TRUE) %>%
     hc_tooltip(
       formatter = JS(paste0("function (tooltip) {