feat(theme): Add tomorrow-night

**What?**

1. Add tomorrow night github.com/chriskempson/tomorrow-theme theme and screenshot.

**Why?**

It's a nice theme!

Author: cashpw

doc/themes.md

@@ -65,6 +65,8 @@ Note: screenshots were generated using [this config](../gen-screenshots/screensh
 ![ctp-macchiato](../img/themes/ctp-macchiato.png)
 * `ctp-mocha`
 ![ctp-mocha](../img/themes/ctp-mocha.png)
+* `tomorrow-night`
+![tomorrow-night](../img/themes/tomorrow-night.png)
 
 # Available icon sets
 

files/themes/tomorrow-night.toml

@@ -0,0 +1,28 @@
+# Tomorrow (Night)
+#
+# Foreground: #c5c8c6
+# Background: #1d1f21
+# Selection: #373b41
+# Current line: #282a2e
+# Comment: #969896
+# Red: #cc6666
+# Orange: #de935f
+# Yellow: #f0c674
+# Green: #b5bd68
+# Aqua: #8abeb7
+# Blue: #81a2be
+# Purple: #b294bb
+
+idle_bg = "#373b41" # Selection
+idle_fg = "#c5c8c6" # Foreground
+info_bg = "#81a2be" # Blue
+info_fg = "#1d1f21" # Background
+good_bg = "#b5bd68" # Green
+good_fg = "#1d1f21" # Background
+warning_bg = "#f0c674" # Yellow
+warning_fg = "#1d1f21" # Background
+critical_bg = "#cc6666" # Red
+critical_fg = "#1d1f21" # Background
+separator = "\ue0b2"
+separator_bg = "auto"
+separator_fg = "auto"