tidy-up: Markdown, clang-format nits

- drop leading indent from Markdown.
- switch to Markdown section markers where missing.
- move `&&` and `||` to the end of the line (C, Perl).
- openssl: add parenthesis to an if sub-expression.
- misc clang-format nits.
- unfold Markdown links.
- SSL-PROBLEMS.md: drop stray half code-fence.

Closes #20402

src/tool_easysrc.c

@@ -64,7 +64,7 @@ static const char * const srchard[] = {
   "",
   NULL
 };
-static const char *const srcend[]={
+static const char *const srcend[] = {
   "",
   "  return (int)ret;",
   "}",