Add greyscale theme (#204)

contrib/themes/README.md

@@ -21,6 +21,17 @@ Contributed by **[@crdpa](https://github.com/crdpa)**.
 ![screenshot of dracula theme](https://user-images.githubusercontent.com/61637474/99983210-53d2e900-2d8a-11eb-9ab7-12dc10c2933a.png)
 </details>
 
+## Greyscale Light
+
+Contributed by **[@leifmetcalf](https://github.com/leifmetcalf)**.
+![screenshot of greyscale light theme](https://user-images.githubusercontent.com/35786377/109232516-53d10200-782d-11eb-9863-4bb745d27195.png)
+
+<details>
+<summary>More screenshots</summary>
+
+![screenshot of greyscale light theme](https://user-images.githubusercontent.com/35786377/109232522-55022f00-782d-11eb-93a2-4d50c61317c5.png)
+</details>
+
 ## Gruvbox
 
 Contributed by **[@Skraylet](https://github.com/Skraylet)**.

contrib/themes/greyscale-light.toml

@@ -0,0 +1,47 @@
+[theme]
+bg = "#ffffff"
+tab_num = "#000000"
+tab_divider = "#000000"
+bottombar_label = "#ffffff"
+bottombar_text = "#ffffff"
+bottombar_bg = "#000000"
+
+hdg_1 = "#000000"
+hdg_2 = "#000000"
+hdg_3 = "#000000"
+amfora_link = "#000000"
+foreign_link = "#7f7f7f"
+link_number = "#000000"
+regular_text = "#000000"
+quote_text = "#000000"
+preformatted_text = "#000000"
+list_text = "#000000"
+
+btn_bg = "#efefef"
+btn_text = "#000000"
+
+dl_choice_modal_bg = "#efefef"
+dl_choice_modal_text = "#000000"
+dl_modal_bg = "#efefef"
+dl_modal_text = "#000000"
+info_modal_bg = "#efefef"
+info_modal_text = "#000000"
+error_modal_bg = "#efefef"
+error_modal_text = "#000000"
+yesno_modal_bg = "#efefef"
+yesno_modal_text = "#000000"
+tofu_modal_bg = "#efefef"
+tofu_modal_text = "#000000"
+subscription_modal_bg = "#efefef"
+subscription_modal_text = "#000000"
+
+input_modal_bg = "#efefef"
+input_modal_text = "#000000"
+input_modal_field_bg = "#ffffff"
+input_modal_field_text = "#000000"
+
+bkmk_modal_bg = "#efefef"
+bkmk_modal_text = "#000000"
+bkmk_modal_label = "#000000"
+bkmk_modal_field_bg = "#ffffff"
+bkmk_modal_field_text = "#000000"