feat(tui)!: use transparent background by default (#193)

* feat(tui)!: Use transparent background by default

Right now the default background color of systeroid-tui is black, which
is not great when it comes to different color schemes.

This change replaces `black` with `reset` as the default.
(reset means transparent in this context)

BREAKING CHANGE: Use transparent background by default

* docs(README): add info

* refactor: change version number 0.5.0 -> 0.4.6

Author: tessus

README.md

@@ -572,6 +572,7 @@ Press <kbd>c</kbd> to show the options menu for copying the name, value, or docu
 #### Changing the colors
 
 Use `--bg-color` and `--fg-color` arguments to customize the colors of the terminal user interface.
+A transparent background is used by default.
 
 ```sh
 # use a color name for setting the foreground color
@@ -580,7 +581,7 @@ systeroid-tui --fg-color blue
 # use hexadecimal values for setting foreground/background colors
 systeroid-tui --bg-color ffff99 --fg-color 003366
 
-# use transparent background
+# use transparent background (default as of 0.4.6)
 systeroid-tui --bg-color reset
 ```
 

systeroid-tui/src/args.rs

@@ -70,7 +70,7 @@ impl Args {
         opts.optopt(
             "",
             "bg-color",
-            "set the background color [default: black]",
+            "set the background color [default: reset (transparent)]",
             "<color>",
         );
         opts.optopt(
@@ -134,7 +134,7 @@ impl Args {
                     .unwrap_or_else(|| String::from("white")),
                 bg_color: matches
                     .opt_str("bg-color")
-                    .unwrap_or_else(|| String::from("black")),
+                    .unwrap_or_else(|| String::from("reset")),
                 no_docs: matches.opt_present("n"),
                 display_deprecated: matches.opt_present("deprecated"),
                 config: matches