♻️💄 simplify KorAPConnection class instantiations to modern syntax

Update all class instantiations from `new("KorAPConnection")` to `KorAPConnection()`.
This is possible with R >= 4.0.

Change-Id: I01131fb32045e084cafbb9e05cd8ba99f8f20f1b
diff --git a/demo/adjectiveCollocates.R b/demo/adjectiveCollocates.R
index 3d69eaa..346199b 100644
--- a/demo/adjectiveCollocates.R
+++ b/demo/adjectiveCollocates.R
@@ -2,7 +2,7 @@
 library(kableExtra)
 
 
-new("KorAPConnection", verbose = TRUE) %>%
+KorAPConnection(verbose = TRUE) %>%
   auth() %>%
   collocationAnalysis("focus([marmot/p=ADJA] {Gendern})", leftContextSize=1, rightContextSize=0) %>%
   mutate(collocate = paste0('<a href="', webUIRequestUrl, '">', collocate, '</a>')) %>%