data scraper for Changelogs

[Julow]

This adds a tool that detects missing changelogs by looking at projects' release pages. My intention is to write a GA that will notify maintainers (perhaps by opening draft PRs) for new releases. Does that sound good ?

This will not help catching new releases in its current form but it can be used to add changelogs that are already missing. Here's its output:

Downloading https://github.com/ocaml/dune/releases.atom ... done 
Downloading https://github.com/tarides/dune-release/releases.atom ... done 
Downloading https://github.com/realworldocaml/mdx/releases.atom ... done 
No changelog entry for "mdx" version "2.5.0"

No changelog entry for "mdx" version "Release 0.3.3"

No changelog entry for "mdx" version "Release 0.3.2"

No changelog entry for "mdx" version "Release 0.3.1"

Downloading https://github.com/ocaml/merlin/releases.atom ... done 
No changelog entry for "merlin" version "5.4.1-503"

No changelog entry for "merlin" version "5.4-503"

No changelog entry for "merlin" version "4.18-414"

No changelog entry for "merlin" version "5.3-502"

No changelog entry for "merlin" version "4.17.1-414"

No changelog entry for "merlin" version "4.17.1-501"

No changelog entry for "merlin" version "5.2.1-502"

No changelog entry for "merlin" version "4.17-414"

No changelog entry for "merlin" version "4.17-501"

No changelog entry for "merlin" version "5.2-502"

Downloading https://github.com/ocaml/ocaml/releases.atom ... done 
No changelog entry for "ocaml" version "5.2.1-rc1"

Downloading https://github.com/ocaml/ocaml-lsp/releases.atom ... done 
No changelog entry for "ocaml-lsp" version "1.22.0"

No changelog entry for "ocaml-lsp" version "1.21.0"

No changelog entry for "ocaml-lsp" version "1.20.0"

Downloading https://github.com/ocaml-ppx/ocamlformat/releases.atom ... done 
Downloading https://github.com/OCamlPro/ocp-indent/releases.atom ... done 
No changelog entry for "ocp-indent" version "nlfork-1.5.5"

No changelog entry for "ocp-indent" version "1.8.2"

No changelog entry for "ocp-indent" version "nlfork-1.5.4"

No changelog entry for "ocp-indent" version "nlfork-1.5.3"

Downloading https://github.com/ocaml/odoc/releases.atom ... done 
No changelog entry for "odoc" version "3.0.0~beta1"

No changelog entry for "odoc" version "2.4.4"

No changelog entry for "odoc" version "2.4.3"

No changelog entry for "odoc" version "2.2.2"

Downloading https://github.com/ocaml-ppx/ocaml-migrate-parsetree/releases.atom ... d
one 
No changelog entry for "omp" version "v1.7.0"

Downloading https://github.com/ocaml/opam//releases.atom ... done 
Downloading https://github.com/ocaml-opam/opam-publish/releases.atom ... done 
No changelog entry for "opam-publish" version "2.5.0"

No changelog entry for "opam-publish" version "2.4.0"

No changelog entry for "opam-publish" version "2.3.1"

Downloading https://github.com/ocaml-ppx/ppxlib/releases.atom ... done 
No changelog entry for "ppxlib" version "0.34.0"

Downloading https://github.com/ocaml-community/utop/releases.atom ... done 
No changelog entry for "utop" version "Utop 2.15.0"