I want to match the word "regex"
in a given piece of text irrespective of capital letters.
'I like regex a lot.'
should match.
'I like REGEX a lot.'
should match.
'I like Regex a lot.'
should match.
'I like ReGeX a lot.'
should match.
'I like RegeX a lot.'
should match.
'I like regexa lot'
should not match.
'I like regex22 lot'
should not match.