update ePub and PDF

- new LispWorks section
- re-written dates and times section (local-times library)
- updated database section, with updated Mito usage
- updated CI section with newer tools
- emacs: mentioned C-c C-j eval in repl
- iteration: about nconcing to return a flat list
- Added (clrhash) to data-structures.md
- more typo and grammar fixes, small additions

contributors.md

@@ -34,30 +34,41 @@ The contributors on Github are:
 * Johan Sjölén
 * Mariano Montone
 * albertoriva
+* Daniel Keogh
+* Matteo Landi
 * Nisar Ahmad
 * Nisen
 * Vityok
 * ozten
+* Ahmad Edrisy
 * Amol Dosanjh
 * Andrew
 * Andrew Hill
+* André Alexandre Gomes
 * Bibek Panthi
+* Blue
 * Bo Yao
+* Brandon Hale
 * Burhanuddin Baharuddin
 * Coin Okay
 * Danny Yue
+* Eric Timmons
 * HiPhish
+* Justin
 * Kevin Layer
 * LdBeth
 * Matthew Kennedy
 * Momozor
+* Noor
 * Paul Donnelly
 * Pavel Kulyov
 * R Primus
 * Salad Tea
 * Victor Anyakin
 * convert-repo
+* jgart
 * jthing
+* mavis
 * mwgkgk
 * paul-donnelly
 * various-and-sundry

metadata.txt

@@ -9,7 +9,7 @@ creator:
  text: The Common Lisp Cookbook contributors
 identifier:
 publisher:
-rights: © 2021 March, 31, vindarel <vindarel@mailz.org>.
+rights: © 2021 July, 29, vindarel <vindarel@mailz.org>.
  This e-book is free of charge, but you can [pay what you want](https://ko-fi.com/s/01fee22a32) for it.
 cover-image: orly-cover.png
 ...