Feature additions (#11)

* add color table support (using alternating colorization of rows) using new flag `-L`
* add config file support (HCL format) using `~/.config/tablizer/config` or `-f <file>` so the user can customize colors
* removed golang 1.17 support

config.hcl

@@ -0,0 +1,12 @@
+# supported  colors:
+# black, blue,  cyan, darkGray, default, green,  lightBlue, lightCyan,
+# lightGreen,   lightMagenta,   lightRed,   lightWhite,   lightYellow,
+# magenta, red, white, yellow
+BG             = "lightGreen"
+FG             = "white"
+HighlightBG    = "lightGreen"
+HighlightFG    = "white"
+NoHighlightBG  = "white"
+NoHighlightFG  = "lightGreen"
+HighlightHdrBG = "red"
+HighlightHdrFG = "white"