Check for incomplete URLs

[koppor]

For consistency, all links should start with https://, shouldn't they?

Wrong:

[#14233](github.com/JabRef/jabref/pull/14233)

- - We added "IEEE" as another option for parsing plain text citations. [#14233](github.com/JabRef/jabref/pull/14233)
+ - We added "IEEE" as another option for parsing plain text citations. [#14233](https://github.com/JabRef/jabref/pull/14233)

---

File: https://github.com/JabRef/jabref/blob/a0570c9cc6034cdebaebf0bcdf191322c37e1259/CHANGELOG.md#added

Current check:

$ jbang heylogs@nbbrd check CHANGELOG.md
[jbang] Resolving dependencies...
[jbang]    com.github.nbbrd.heylogs:heylogs-cli:0.14.1
[jbang] Dependencies resolved
[jbang] Building jar for heylogs.java...
CHANGELOG.md
    42:1  error  Heading [Unreleased] has no entries for REMOVED                                                                                                                                                                                     no-empty-group
   786:1  error  Imbalanced braces found in '- JabRef is now more relaxed when parsing field content: In case a field content ended with `\`, the combination `\}` was treated as plain `}`. [#9668](https://github.com/JabRef/jabref/issues/9668)'  imbalanced-braces
  1790:1  error  Missing ref link                                                                                                                                                                                                                    all-h2-contain-a-version

  3 problems