updated readme

Author: xelatihy

README.md

@@ -143,9 +143,11 @@ target_link_libraries(myprogram PUBLIC fast_float)
 
 ## Using as single header
 
-The script `amalgamate.py` may be used to generate a single header version of the library is so desired.
+The script `scripts/amalgamate.py` may be used to generate a single header 
+version of the library if so desired.
 Just run the script from the root directory of this repository. 
-You can customize the license type and output file is desired as described in the command line help.
+You can customize the license type and output file if desired as described in
+the command line help.
 
 ## Credit