theme: 📝 ✨ add docs for partial theme

Signed-off-by: zwPapEr <[email protected]>

CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Added support for the MISSING / mi= dircolors variable for broken symlink targets.
 - Add support for theme from [zwpaper](https://github.com/zwpaper) [#452](https://github.com/Peltoche/lsd/pull/452)
+- Update theme to support partial themes [zwpaper](https://github.com/zwpaper) [#591](https://github.com/Peltoche/lsd/pull/591)
 - Update minimal rust version to 1.42.0 from [zwpaper](https://github.com/zwpaper) [#534](https://github.com/Peltoche/lsd/issues/534)
 - [`NO_COLOR`](https://no-color.org/) environment variable support from [AnInternetTroll](https://github.com/aninternettroll)
 ### Changed
@@ -17,7 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Add `--config-file` flag to read configuration file from a custom location
 - Clarify custom date format for `date` field in configuration file in the README.
 ### Fixed
-- Support all `strftime` like formatting [#532](https://github.com/Peltoche/lsd/issues/532)   
+- Support all `strftime` like formatting [#532](https://github.com/Peltoche/lsd/issues/532)
 
 ## [0.20.1] - 2021-03-07
 ### Fixed

README.md

@@ -228,17 +228,16 @@ Check [Theme file content](#theme-file-content) for details.
 ### Theme file content
 
 Theme file use the [crossterm](https://crates.io/crates/crossterm)
-configure the colors, check [crossterm](https://docs.rs/crossterm/0.20.0/crossterm/style/enum.Color.html)
-for the supported colors.
+to configure the colors, check [crossterm](https://docs.rs/crossterm/0.20.0/crossterm/style/enum.Color.html)
+for supported colors.
 
 Color table: https://upload.wikimedia.org/wikipedia/commons/1/15/Xterm_256color_chart.svg
 
-Please notice that color value would ignore case, both lowercase and UPPERCASE is supported.
+Please notice that color values would ignore the case, both lowercase and UPPERCASE is supported.
 
 This is the default theme scheme shipped with `lsd`.
 
 ```yaml
-default: 245
 user: 230
 group: 187
 permission:
@@ -265,8 +264,11 @@ links:
 tree-edge: 245
 ```
 
-The `default` item is required while the others are optional,
-it will use the `default` value as color for the items missed.
+When creating a theme for `lsd`, you can specify any part of the default theme,
+and then change its colors, the items missed would fallback to use the default colors.
+
+Please also notice that an empty theme is **NOT** supported due to
+[a bug in serde lib](https://github.com/dtolnay/serde-yaml/issues/86).
 
 ## External Configurations