nu-table/ Add table.indent configuration (#9983)

Hi there.

Am I got it right?

ref: https://github.com/zhiburt/tabled/issues/358
cc: @fdncred

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Signed-off-by: Maxim Zhiburt <zhiburt@gmail.com>

crates/nu-utils/src/sample_config/default_config.nu

@@ -158,6 +158,7 @@ $env.config = {
         mode: rounded # basic, compact, compact_double, light, thin, with_love, rounded, reinforced, heavy, none, other
         index_mode: always # "always" show indexes, "never" show indexes, "auto" = show indexes when a table has "index" column
         show_empty: true # show 'empty list' and 'empty record' placeholders for command output
+        padding: { left: 1, right: 1 } # a left right padding of each column in a table
         trim: {
             methodology: wrapping # wrapping or truncating
             wrapping_try_keep_words: true # A strategy used by the 'wrapping' methodology