Add new style - "hr" (#513)

Author: Soubik Bhui

Diff for: styles/hr_dark.go

@@ -0,0 +1,17 @@
+package styles
+
+import (
+	"github.com/alecthomas/chroma"
+)
+
+// Theme based on HackerRank Dark Editor theme
+var HrDark = Register(chroma.MustNewStyle("hrdark", chroma.StyleEntries{
+	chroma.Comment:      "italic #828b96",
+	chroma.Keyword:      "#ff636f",
+	chroma.OperatorWord: "#ff636f",
+	chroma.Name:         "#58a1dd",
+	chroma.Literal:      "#a6be9d",
+	chroma.Operator:     "#ff636f",
+	chroma.Background:   "#1d2432",
+	chroma.Other:        "#fff",
+}))

Diff for: styles/hr_high_contrast.go

@@ -0,0 +1,19 @@
+package styles
+
+import (
+	"github.com/alecthomas/chroma"
+)
+
+// Theme based on HackerRank High Contrast Editor Theme
+var HrHighContrast = Register(chroma.MustNewStyle("hr_high_contrast", chroma.StyleEntries{
+	chroma.Comment:              "#5a8349",
+	chroma.Keyword:              "#467faf",
+	chroma.OperatorWord:         "#467faf",
+	chroma.Name:                 "#ffffff",
+	chroma.LiteralString:        "#a87662",
+	chroma.LiteralNumber:        "#fff",
+	chroma.LiteralStringBoolean: "#467faf",
+	chroma.Operator:             "#e4e400",
+	chroma.Background:           "#000",
+	chroma.Other:                "#d5d500",
+}))