ots-side-by-side.1: escape ascii-art sections
ots-side-by-side.1: escape ascii-art sections

This patch fixes the warnings for the following command:

	LC_ALL=C.UTF-8 MANROFFSEQ='' MANWIDTH=80 \
	    man --warnings -E UTF-8 -l -Tutf8 -Z <file> >/dev/null

Warnings fixed:

	42: '\ ' is not allowed in a name
	93: warning: macro '#*' not defined
	101: '\ ' is not allowed in a name
	135: '\ ' is not allowed in a name
	135: warning: macro '#+' not defined
	42: warning: macro '###+.#.' not defined
	61: '\ ' is not allowed in a name
	61: warning: macro '##' not defined
	62: '\ ' is not allowed in a name
	63: '\ ' is not allowed in a name
	84: '\ ' is not allowed in a name
	84: warning: macro '##+.#+' not defined
	93: '\ ' is not allowed in a name

khaledhosny/ots