Don't use a mix of tabs and spaces (#17045)

This PR fixes some spots in the docs and the `install.sh` script that
were using a mix of tabs and spaces.

We should just be using spaces.

Release Notes:

- N/A

script/install.sh

@@ -39,11 +39,11 @@ main() {
         }
     elif which wget >/dev/null 2>&1; then
         curl () {
-    	    wget -O- "$@"
+            wget -O- "$@"
         }
     else
-    	echo "Could not find 'curl' or 'wget' in your path"
-    	exit 1
+        echo "Could not find 'curl' or 'wget' in your path"
+        exit 1
     fi
 
     "$platform" "$@"