Fix tables in README

Author: emilv

README.md

@@ -53,9 +53,8 @@ I ran this benchmarks on a 16 MHz Arduino Pro Mini. Sizes are estimates.
 sort2 is specialized for two-element arrays: it is a macro with a simple ìf` statement.
 
 | Sorting method      | Compiled size |
-+---------------------+---------------+
+| ------------------- | ------------- |
 | Baseline, no sort   | 2 326 bytes   |
-+---------------------+---------------+
 | qsort, standard lib | 3 510 bytes   |
 | gnome sort 2        | 2 388 bytes   |
 | bubblesort          | 2 354 bytes   |
@@ -67,9 +66,8 @@ sort2 is specialized for two-element arrays: it is a macro with a simple ìf` st
 sort3 is specialized for three-element arrays, similar to sort2
 
 | Sorting method      | Compiled size |
-+---------------------+---------------+
+| ------------------- | ------------- |
 | Baseline, no sort   | 2 352 bytes   |
-+---------------------+---------------+
 | qsort, standard lib | 3 536 bytes   |
 | gnome sort 2        | 2 448 bytes   |
 | bubblesort          | 2 426 bytes   |
@@ -79,9 +77,8 @@ sort3 is specialized for three-element arrays, similar to sort2
 ### 20 elements
 
 | Sorting method      | Compiled size |
-+---------------------+---------------+
+| ------------------- | ------------- |
 | Baseline, no sort   | 2 322 bytes   |
-+---------------------+---------------+
 | qsort, standard lib | 3 504 bytes   |
 | gnome sort 2        | 2 400 bytes   |
 | bubblesort          | 2 370 bytes   |