Improve messages regarding font installation

In commit d8318d8db866 ("Add font installation check"), there was
typos already fixed by commit adc5a0ed9702 ("Fix typo "baloon" ->
"balloon"").
However, it breaks adjustment of "##" charactors in the warning
messages.
This commit fixes them.
It also improves explanation of item 1 in FAQ-BUILD.txt by adding
a reference to item 1 of FAQ.txt.
It also adds a comment in Figure 1.1 that refers to item 1 in
FAQ.txt

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
2 files changed