make text center of div bootstrap code example

Example 1: centre text bootstrap

	
 hello world

Example 2: center text with boostrap

Left aligned text on all viewport sizes.
Center aligned text on all viewport sizes.
 //CENTER TEXT
Right aligned text on all viewport sizes.

Left aligned text on viewports sized SM (small) or wider.
Left aligned text on viewports sized MD (medium) or wider.
Left aligned text on viewports sized LG (large) or wider.
Left aligned text on viewports sized XL (extra-large) or wider.