Fix typo/example

Author: zohairawan

src/files.md

@@ -4,6 +4,6 @@ Files are how you store information
 on a[^normal] computer so that it can still be there when your program
 is done running.
 
-As such, read files and writing files are tasks you will often want to do.
+As such, reading files and writing files are tasks you will often want to do.
 
 [^normal]: *normal

src/integers_ii/base_16_integer_literals.md

@@ -33,4 +33,4 @@ deals with colors in RGB - Red, Green, Blue - format. `0xFFFFFF` is white, `0xFF
 
 
 [^everything]: Okay to be real with you, every number system is a base 10 system.
-Even if what you call "10" is what we would call "sixteen", you always wrap around your base when you write "10." If that doesn't make sense it doesn't matter, but its fascinating to me.
+Even if what you call "10" is what we would call "sixteen", you always wrap around your base when you write "10." If that doesn't make sense it doesn't matter, but it's fascinating to me.

src/objects/equals_and_hashCode.md

@@ -63,9 +63,9 @@ class Main {
         String c = "bca";
 
         IO.println(a.hashCode());
-        // a.equals(b) will return true, so they will have the same hash code
+        // a.equals(b) will return true, so they may or may not have the same hash code
         IO.println(b.hashCode());
-        // a.equals(c) will return false, so they may or may not have the same hash code
+        // a.equals(c) will return false, so it's assumed they have a different hash code
         IO.println(c.hashCode());
 
         Thing t1 = new Thing();