Add _ZO_FZF_OPTS_FILE environment variable

zoxide now recognizes `_ZO_FZF_OPTS_FILE` environment variable, in
addition to `_ZO_FZF_OPTS`.

src/cmd/query.rs

@@ -92,6 +92,11 @@ impl Query {
 
     fn get_fzf() -> Result<FzfChild> {
         let mut fzf = Fzf::new()?;
+
+        if let Some(fzf_opts_file) = config::fzf_opts_file() {
+            fzf.env("FZF_DEFAULT_OPTS_FILE", fzf_opts_file);
+        }
+
         if let Some(fzf_opts) = config::fzf_opts() {
             fzf.env("FZF_DEFAULT_OPTS", fzf_opts)
         } else {

src/config.rs

@@ -47,6 +47,11 @@ pub fn fzf_opts() -> Option<OsString> {
     env::var_os("_ZO_FZF_OPTS")
 }
 
+pub fn fzf_opts_file() -> Option<OsString> {
+    env::var_os("_ZO_FZF_OPTS_FILE")
+}
+
+
 pub fn maxage() -> Result<Rank> {
     env::var_os("_ZO_MAXAGE").map_or(Ok(10_000.0), |maxage| {
         let maxage = maxage.to_str().context("invalid unicode in _ZO_MAXAGE")?;