org-startup-truncated default should be nil [legibility 2/6]

[Texas Cyberthal]

#+begin_src elisp
(org-startup-truncated nil)
#+end_src

Line truncation is necessary for code but anathema for prose. Prose
lines need visual wrap as windows resize, so that texts can be
compared easily.

Advanced Org uses such as large tables require line truncation. Tables
are a code-like fixed-pitch feature.

Users will write a paragraph of prose longer than the screen well
before they discover a need for line truncation, such as long lines of
code or wide tables. Users who need line truncation are likely to know
about it, whereas users who need line truncation off are unlikely to
know what it's called.

Learning about line truncation is an unnecessary hurdle for beginners.
Therefore the default should be nil.