📝 typo/grammar

Author: wdecoster

source/docs/a8.primitive_data_types.md

@@ -195,7 +195,7 @@ let f = 3.14; // Equals to `let f: f64 = 3.14;`
 let a = 5i8; // Equals to `let a: i8 = 5;`
 
 let b = 100_000_000; // Equals to `let b = 100000000;`
-// 💡 The placements of _s are not strict. ex. 10000_0000 also valid.
+// 💡 The placements of _s are not strict. ex. 10000_0000 is also valid.
 
 let pi = 3.141_592_653_59f64; // Equals to `let pi: f64 = 3.14159265359`