add subtitle/closed caption icons (#1050)

add subtitle/closed caption icons

uses `U+F015E`, `󰅞` for `.890`, `.cip`, `.sbv`, `.scc`, `smi`, and good
old `.vtt` <!-- over the hedge reference, best animated movie (: -->

Signed-off-by: Wei Zhang <kweizh@gmail.com>
Co-authored-by: Wei Zhang <kweizh@gmail.com>

Author: RuralAnemone

src/theme/icon.rs

@@ -409,6 +409,7 @@ impl IconTheme {
             ("7", "\u{f02d}"),               // ""
             ("7z", "\u{f410}"),              // ""
             ("8", "\u{f02d}"),               // ""
+            ("890", "\u{f015e}"),            // "󰅞"
             ("a", "\u{e624}"),               // ""
             ("ai", "\u{e7b4}"),              // ""
             ("ape", "\u{f001}"),             // ""
@@ -436,6 +437,7 @@ impl IconTheme {
             ("bz2", "\u{f410}"),             // ""
             ("cc", "\u{e61d}"),              // ""
             ("cfg", "\u{e615}"),             // ""
+            ("cip", "\u{f015e}"),            // "󰅞"
             ("cjs", "\u{e74e}"),             // ""
             ("class", "\u{e738}"),           // ""
             ("cljs", "\u{e76a}"),            // ""
@@ -625,7 +627,10 @@ impl IconTheme {
             ("ps1", "\u{f489}"),             // ""
             ("psd", "\u{e7b8}"),             // ""
             ("pub", "\u{f0306}"),            // "󰌆"
+            ("sbv", "\u{f015e}"),            // "󰅞"
+            ("scc", "\u{f015e}"),            // "󰅞"
             ("slt", "\u{f0221}"),            // "󰈡"
+            ("smi", "\u{f015e}"),            // "󰅞"
             ("pxm", "\u{f1c5}"),             // ""
             ("pyc", "\u{e606}"),             // ""
             ("py", "\u{e606}"),              // ""
@@ -703,6 +708,7 @@ impl IconTheme {
             ("video", "\u{f008}"),           // ""
             ("vim", "\u{e62b}"),             // ""
             ("vlc", "\u{f0411}"),            // "󰐑"
+            ("vtt", "\u{f015e}"),            // "󰅞"
             ("vue", "\u{f0844}"),            // "󰡄"
             ("wav", "\u{f001}"),             // ""
             ("webm", "\u{f008}"),            // ""