theme: add nu4a

Hi all

I have created this theme recently
I will be glad if you kindly accept it in your repo
It's based on Agnoster theme, but is way cooler

Best regards.

closes #482

themes/nu4a.omp.json

@@ -0,0 +1,88 @@
+{
+  "$schema": "https://raw.githubusercontent.com/JanDeDobbeleer/oh-my-posh/main/themes/schema.json",
+  "blocks": [
+    {
+      "type": "prompt",
+      "alignment": "left",
+      "segments": [
+        {
+          "type": "root",
+          "style": "powerline",
+          "powerline_symbol": "\uE0B0",
+          "foreground": "#100e23",
+          "background": "#ff3026",
+          "properties": {
+            "root_icon": "\uF0E7"
+          }
+        },
+        {
+          "type": "session",
+          "style": "powerline",
+          "powerline_symbol": "\uE0B0",
+          "foreground": "#100e23",
+          "background": "#cfcfc4"
+        },
+        {
+          "type": "path",
+          "style": "powerline",
+          "powerline_symbol": "\uE0B0",
+          "foreground": "#100e23",
+          "background": "#ec9706",
+          "properties" : {
+              "home_icon": "\uF7DB",
+              "folder_icon": "\uF115",
+              "folder_separator_icon": " \uE0B1 ",
+              "style": "full"
+          }
+        },
+        {
+          "type": "git",
+          "style": "powerline",
+          "powerline_symbol": "\uE0B0",
+          "foreground": "#193549",
+          "background": "#95ffa4"
+        },
+        {
+          "type": "python",
+          "style": "powerline",
+          "powerline_symbol": "\uE0B0",
+          "foreground": "#100e23",
+          "background": "#906cff",
+          "properties": {
+            "prefix": " \uE235 "
+          }
+        }
+      ]
+    },
+    {
+      "type": "rprompt",
+      "alignment": "right",
+      "segments": [
+        {
+          "type": "exit",
+          "style": "diamond",
+          "leading_diamond": "\ue0c2",
+          "trailing_diamond": "\ue0c0",
+          "foreground": "#ffffff",
+          "background": "#ff4040",
+          "properties": {
+            "display_exit_code": false,
+            "always_enabled": false,
+            "prefix": " \ue70f"
+          }
+        },
+        {
+          "type": "executiontime",
+          "style": "diamond",
+          "foreground": "#fafafa",
+          "background": "#2f2f2f",
+          "leading_diamond": "\ue0b2",
+          "properties": {
+            "style": "austin"
+          }
+        }
+      ]
+    }
+  ],
+  "final_space": true
+}