add keyword spacing and detection of templates exp

Adding two rules. The first is convention in the project already and the second is very useful for spotting incorrect curly braces in e.g. origin strings, slave.origin = "{He} was born a slave."

https://eslint.org/docs/rules/keyword-spacing

https://eslint.org/docs/rules/no-template-curly-in-string#disallow-template-literal-placeholder-syntax-in-regular-strings-no-template-curly-in-string