Update Index.rst

"Straightforward" meaning "obvious" does not use a hyphen. Separately (straight forward) would means "straight ahead".
"On the left side," leaves the question open as to "The right side". It leaves a feeling that there is something missing to balance out the TypoScript syntax.
Merge branch 'patch-3' of https://github.com/timotheonb/TYPO3CMS-Tutorial-Typoscript45Minutes into timotheonb-patch-3
Improved description of TypoScript syntax.
Added example of TypoScript syntax.
Merge branch 'timotheonb-patch-3' into latest after small
improvements.