upgrade 0.83 (#563)

fix `<duration> | into string`
`gn` allows init git repo in current directory, and use `main` as
default branch

Co-authored-by: agent <agent@nuc>

modules/git/git-v2.nu

@@ -182,8 +182,12 @@ export def-env gn [
     --init (-i):      bool     # git init
 ] {
      if $init {
-        git init $repo
-        cd $repo
+        if ($repo | is-empty) {
+            git init --initial-branch main
+        } else {
+            git init $repo --initial-branch main
+            cd $repo
+        }
         if $submodule {
             git submodule init
         }

modules/prompt/powerline/power.nu

@@ -92,10 +92,7 @@ def time_segment [] {
 def logtime [msg act] {
     let start = (date now)
     let result = (do $act)
-    let period = ((date now) - $start
-        | into duration -c ns
-        | into string
-        | str replace ' ' '')
+    let period = ($"((date now) - $start | into duration -c ns)" | str replace ' ' '')
 
     echo $'($start | date format '%Y-%m-%d_%H:%M:%S%z')(char tab)($period)(char tab)($msg)(char newline)'
     | save -a ~/.cache/nushell/power_time.log