FEATURE: add term-dark and term-light themes from main nushell (#500)

* add `term-dark` and `term-light` themes from main `nushell`

* rename the themes: `{term=>nushell}-{dark,light}`

themes/themes/nushell-dark.nu

@@ -0,0 +1,83 @@
+export def main [] { return {
+    # color for nushell primitives
+    separator: white
+    leading_trailing_space_bg: { attr: n } # no fg, no bg, attr none effectively turns this off
+    header: green_bold
+    empty: blue
+    # Closures can be used to choose colors for specific values.
+    # The value (in this case, a bool) is piped into the closure.
+    bool: {|| if $in { 'light_cyan' } else { 'light_gray' } }
+    int: white
+    filesize: {|e|
+      if $e == 0b {
+        'white'
+      } else if $e < 1mb {
+        'cyan'
+      } else { 'blue' }
+    }
+    duration: white
+    date: {|| (date now) - $in |
+      if $in < 1hr {
+        'purple'
+      } else if $in < 6hr {
+        'red'
+      } else if $in < 1day {
+        'yellow'
+      } else if $in < 3day {
+        'green'
+      } else if $in < 1wk {
+        'light_green'
+      } else if $in < 6wk {
+        'cyan'
+      } else if $in < 52wk {
+        'blue'
+      } else { 'dark_gray' }
+    }
+    range: white
+    float: white
+    string: white
+    nothing: white
+    binary: white
+    cellpath: white
+    row_index: green_bold
+    record: white
+    list: white
+    block: white
+    hints: dark_gray
+
+    shape_and: purple_bold
+    shape_binary: purple_bold
+    shape_block: blue_bold
+    shape_bool: light_cyan
+    shape_closure: green_bold
+    shape_custom: green
+    shape_datetime: cyan_bold
+    shape_directory: cyan
+    shape_external: cyan
+    shape_externalarg: green_bold
+    shape_filepath: cyan
+    shape_flag: blue_bold
+    shape_float: purple_bold
+    # shapes are used to change the cli syntax highlighting
+    shape_garbage: { fg: white bg: red attr: b}
+    shape_globpattern: cyan_bold
+    shape_int: purple_bold
+    shape_internalcall: cyan_bold
+    shape_list: cyan_bold
+    shape_literal: blue
+    shape_match_pattern: green
+    shape_matching_brackets: { attr: u }
+    shape_nothing: light_cyan
+    shape_operator: yellow
+    shape_or: purple_bold
+    shape_pipe: purple_bold
+    shape_range: yellow_bold
+    shape_record: cyan_bold
+    shape_redirection: purple_bold
+    shape_signature: green_bold
+    shape_string: green
+    shape_string_interpolation: cyan_bold
+    shape_table: blue_bold
+    shape_variable: purple
+    shape_vardecl: purple
+}}

themes/themes/nushell-light.nu

@@ -0,0 +1,83 @@
+export def main [] { return {
+    # color for nushell primitives
+    separator: dark_gray
+    leading_trailing_space_bg: { attr: n } # no fg, no bg, attr none effectively turns this off
+    header: green_bold
+    empty: blue
+    # Closures can be used to choose colors for specific values.
+    # The value (in this case, a bool) is piped into the closure.
+    bool: {|| if $in { 'dark_cyan' } else { 'dark_gray' } }
+    int: dark_gray
+    filesize: {|e|
+      if $e == 0b {
+        'dark_gray'
+      } else if $e < 1mb {
+        'cyan_bold'
+      } else { 'blue_bold' }
+    }
+    duration: dark_gray
+  date: {|| (date now) - $in |
+    if $in < 1hr {
+      'purple'
+    } else if $in < 6hr {
+      'red'
+    } else if $in < 1day {
+      'yellow'
+    } else if $in < 3day {
+      'green'
+    } else if $in < 1wk {
+      'light_green'
+    } else if $in < 6wk {
+      'cyan'
+    } else if $in < 52wk {
+      'blue'
+    } else { 'dark_gray' }
+  }
+    range: dark_gray
+    float: dark_gray
+    string: dark_gray
+    nothing: dark_gray
+    binary: dark_gray
+    cellpath: dark_gray
+    row_index: green_bold
+    record: white
+    list: white
+    block: white
+    hints: dark_gray
+
+    shape_and: purple_bold
+    shape_binary: purple_bold
+    shape_block: blue_bold
+    shape_bool: light_cyan
+    shape_closure: green_bold
+    shape_custom: green
+    shape_datetime: cyan_bold
+    shape_directory: cyan
+    shape_external: cyan
+    shape_externalarg: green_bold
+    shape_filepath: cyan
+    shape_flag: blue_bold
+    shape_float: purple_bold
+    # shapes are used to change the cli syntax highlighting
+    shape_garbage: { fg: white bg: red attr: b}
+    shape_globpattern: cyan_bold
+    shape_int: purple_bold
+    shape_internalcall: cyan_bold
+    shape_list: cyan_bold
+    shape_literal: blue
+    shape_match_pattern: green
+    shape_matching_brackets: { attr: u }
+    shape_nothing: light_cyan
+    shape_operator: yellow
+    shape_or: purple_bold
+    shape_pipe: purple_bold
+    shape_range: yellow_bold
+    shape_record: cyan_bold
+    shape_redirection: purple_bold
+    shape_signature: green_bold
+    shape_string: green
+    shape_string_interpolation: cyan_bold
+    shape_table: blue_bold
+    shape_variable: purple
+    shape_vardecl: purple
+}}