feat: remove 'include_private' (#2736)

* feat: remove 'include_private'

As explained in #2517 the 'include_private' flag is confusing and
doesn't work as expected. This commit therefore removes this flag.

* fix: fix tests

* docs: remove redundant private deploy note

api/index.js

@@ -19,7 +19,6 @@ export default async (req, res) => {
     card_width,
     hide_rank,
     show_icons,
-    count_private,
     include_all_commits,
     line_height,
     title_color,
@@ -52,7 +51,6 @@ export default async (req, res) => {
   try {
     const stats = await fetchStats(
       username,
-      parseBoolean(count_private),
       parseBoolean(include_all_commits),
       parseArray(exclude_repo),
     );