config: add bare aliases for "8bit", "24bit"

Without this, setting color-mode using -o required quoting
the values, and then shell-quoting the quotes themselves
(cha -o 'display-color-mode="24bit"').

Instead of more special casing in the TOML parser, we just add aliases
for these enum values that can be parsed using TOML bare string
rules. So now this works:
cha -o display.color-mode=true-color

1 files changed, 7 insertions, 3 deletions

diff --git a/doc/config.md b/doc/config.md
index 36bae2b7..8a078b01 100644
--- a/doc/config.md
+++ b/doc/config.md
@@ -328,10 +328,14 @@ Following is a list of display options:
 
 <tr>
 <td>color-mode</td>
-<td>"monochrome"/"ansi"/"8bit"/"24bit"/"auto"</td>
+<td>"monochrome"/"ansi"/"eight-bit","8bit"/"true-color","24bit"/"auto"</td>
 <td>Set the color mode. "auto" for automatic detection, "monochrome"
-for black on white, "ansi" for ansi colors, "8bit" for 256-color mode, and
-"24bit" for true colors.</td>
+for black on white, "ansi" for ansi colors, "eight-bit" for 256-color mode, and
+"true-color" for true colors.<br>
+"8bit" is a legacy alias of "eight-bit". "24bit" is a legacy alias of
+"true-color". (The only difference is that when overriding these values with
+the `-o` command line switch, you can use "eight-bit" and "true-color"
+without quoting.)</td>
 </tr>
 
 <tr>