feat: horizon theme (#253)

* Added Horizon theme

* Tweaked a colour

* another tweak and updated readme with screenshots.

* Added copyright and luaformatter. Corrected THEMES.md

* fixed lint error

THEMES.md

@@ -85,6 +85,14 @@ lualine try to match your colorscheme.
 <img width='700' src='https://user-images.githubusercontent.com/41551030/108648744-4d085f00-74bc-11eb-8aaa-05a7ca46adec.png'/>
 </p>
 
+### horizon
+<p>
+<img width='700' src='https://user-images.githubusercontent.com/69089176/118903813-70527700-b910-11eb-9d45-1785790ce8e8.png'/>
+<img width='700' src='https://user-images.githubusercontent.com/69089176/118902058-bc9bb800-b90c-11eb-99b8-3b98cbdd01d7.png'/>
+<img width='700' src='https://user-images.githubusercontent.com/69089176/118903506-dab6e780-b90f-11eb-85db-c6227a8caf0c.png'/>
+<img width='700' src='https://user-images.githubusercontent.com/69089176/118902070-c2919900-b90c-11eb-9296-145a99ce52ce.png'/>
+</p>
+
 ### iceberg_dark
 <p>
 <img width='700' src='https://user-images.githubusercontent.com/41551030/108648796-614c5c00-74bc-11eb-8398-cde120ec7746.png'/>

lua/lualine/themes/horizon.lua

@@ -0,0 +1,48 @@
+-- Copyright (c) 2021 Jnhtr
+-- MIT license, see LICENSE for more details.
+-- LuaFormatter off
+local colors = {
+  black        = '#1c1e26',
+  white        = '#6C6F93',
+  red          = '#F43E5C',
+  green        = '#09F7A0',
+  blue         = '#25B2BC',
+  yellow       = '#F09383',
+  gray         = '#E95678',
+  darkgray     = '#1A1C23',
+  lightgray    = '#2E303E',
+  inactivegray = '#1C1E26',
+}
+--LuaFormatter on
+return {
+  normal = {
+    a = {bg = colors.gray, fg = colors.black, gui = 'bold'},
+    b = {bg = colors.lightgray, fg = colors.white},
+    c = {bg = colors.darkgray, fg = colors.white},
+  },
+  insert = {
+    a = {bg = colors.blue, fg = colors.black, gui = 'bold'},
+    b = {bg = colors.lightgray, fg = colors.white},
+    c = {bg = colors.darkgray, fg = colors.white}
+  },
+  visual = {
+    a = {bg = colors.yellow, fg = colors.black, gui = 'bold'},
+    b = {bg = colors.lightgray, fg = colors.white},
+    c = {bg = colors.darkgray, fg = colors.white}
+  },
+  replace = {
+    a = {bg = colors.red, fg = colors.black, gui = 'bold'},
+    b = {bg = colors.lightgray, fg = colors.white},
+    c = {bg = colors.darkgray, fg = colors.white}
+  },
+  command = {
+    a = {bg = colors.green, fg = colors.black, gui = 'bold'},
+    b = {bg = colors.lightgray, fg = colors.white},
+    c = {bg = colors.darkgray, fg = colors.white}
+  },
+  inactive = {
+    a = {bg = colors.inactivegray, fg = colors.lightgray, gui = 'bold'},
+    b = {bg = colors.inactivegray, fg = colors.lightgray},
+    c = {bg = colors.inactivegray, fg = colors.lightgray}
+  }
+}