fix: updating ref to main (not master)

README.md

@@ -1,6 +1,6 @@
 # Macro Core
 
-Much quality. Many standards. The **Macro Core** library exists to save time and development effort! Herein ye shall find a veritable host of MIT-licenced, production quality SAS macros. These are a mix of tools, utilities, functions and code generators that are useful in the context of Application Development on the SAS platform (eg https://datacontroller.io). [Contributions](https://github.com/sasjs/core/blob/master/CONTRIBUTING.md) are welcomed.
+Much quality. Many standards. The **Macro Core** library exists to save time and development effort! Herein ye shall find a veritable host of MIT-licenced, production quality SAS macros. These are a mix of tools, utilities, functions and code generators that are useful in the context of Application Development on the SAS platform (eg https://datacontroller.io). [Contributions](https://github.com/sasjs/core/blob/main/CONTRIBUTING.md) are welcomed.
 
 You can download and compile them all in just two lines of SAS code:
 

make_singlefile.sh

@@ -13,7 +13,7 @@ cat > $OUTFILE <<'EOL'
     'included' in SAS with just 2 lines of code:
 
       filename mc url
-        "https://raw.githubusercontent.com/sasjs/core/master/macrocore.sas";
+        "https://raw.githubusercontent.com/sasjs/core/main/macrocore.sas";
       %inc mc;
 
     The `build.sh` file in the https://github.com/sasjs/core repo