Remove obsidian workspace from git tracking

Remove the file from repo.
Add gitignore for further changes.

.gitignore

+# workspace changes are local to working dir so don't track
+.obsidian/workspace.json

.obsidian/workspace.json

-{
-  "main": {
-    "id": "62a1e3567856e8c2",
-    "type": "split",
-    "children": [
-      {
-        "id": "6142cea3dca7249f",
-        "type": "tabs",
-        "children": [
-          {
-            "id": "627cbb1cc36b80ff",
-            "type": "leaf",
-            "state": {
-              "type": "markdown",
-              "state": {
-                "file": "Welcome.md",
-                "mode": "source",
-                "source": false
-              }
-            }
-          }
-        ]
-      },
-      {
-        "id": "84b7395f2599986d",
-        "type": "tabs",
-        "children": [
-          {
-            "id": "4bd8afa1f5bc651d",
-            "type": "leaf",
-            "state": {
-              "type": "graph",
-              "state": {}
-            }
-          }
-        ]
-      }
-    ],
-    "direction": "vertical"
-  },
-  "left": {
-    "id": "1e976e0c4ff74b31",
-    "type": "split",
-    "children": [
-      {
-        "id": "d8187e7c3f506457",
-        "type": "tabs",
-        "children": [
-          {
-            "id": "16f3004faa86a209",
-            "type": "leaf",
-            "state": {
-              "type": "file-explorer",
-              "state": {
-                "sortOrder": "alphabetical"
-              }
-            }
-          },
-          {
-            "id": "92a5ce2e16d34d8e",
-            "type": "leaf",
-            "state": {
-              "type": "search",
-              "state": {
-                "query": "",
-                "matchingCase": false,
-                "explainSearch": false,
-                "collapseAll": false,
-                "extraContext": false,
-                "sortOrder": "alphabetical"
-              }
-            }
-          },
-          {
-            "id": "889d1657749c012c",
-            "type": "leaf",
-            "state": {
-              "type": "bookmarks",
-              "state": {}
-            }
-          }
-        ]
-      }
-    ],
-    "direction": "horizontal",
-    "width": 300
-  },
-  "right": {
-    "id": "7fc23c61297ba70a",
-    "type": "split",
-    "children": [
-      {
-        "id": "2004e3980b8f0c4b",
-        "type": "tabs",
-        "children": [
-          {
-            "id": "f58c83b7b04650ad",
-            "type": "leaf",
-            "state": {
-              "type": "backlink",
-              "state": {
-                "file": "Welcome.md",
-                "collapseAll": false,
-                "extraContext": false,
-                "sortOrder": "alphabetical",
-                "showSearch": false,
-                "searchQuery": "",
-                "backlinkCollapsed": false,
-                "unlinkedCollapsed": true
-              }
-            }
-          },
-          {
-            "id": "60d1f2681ca2b404",
-            "type": "leaf",
-            "state": {
-              "type": "outgoing-link",
-              "state": {
-                "file": "Welcome.md",
-                "linksCollapsed": false,
-                "unlinkedCollapsed": true
-              }
-            }
-          },
-          {
-            "id": "a3d19368d6fda655",
-            "type": "leaf",
-            "state": {
-              "type": "tag",
-              "state": {
-                "sortOrder": "frequency",
-                "useHierarchy": true
-              }
-            }
-          },
-          {
-            "id": "63129c9bcfd81b28",
-            "type": "leaf",
-            "state": {
-              "type": "outline",
-              "state": {
-                "file": "Welcome.md"
-              }
-            }
-          }
-        ]
-      }
-    ],
-    "direction": "horizontal",
-    "width": 300,
-    "collapsed": true
-  },
-  "left-ribbon": {
-    "hiddenItems": {
-      "switcher:Open quick switcher": false,
-      "graph:Open graph view": false,
-      "canvas:Create new canvas": false,
-      "daily-notes:Open today's daily note": false,
-      "templates:Insert template": false,
-      "command-palette:Open command palette": false
-    }
-  },
-  "active": "627cbb1cc36b80ff",
-  "lastOpenFiles": [
-    "docs/image-factory-pipeline-overview.png",
-    "docs/image-factory-pipeline-overview.excalidraw",
-    "docs/cluster-cicd-design.excalidraw",
-    "docs",
-    "README.md",
-    "Welcome.md"
-  ]
-}
\ No newline at end of file