Added project-specific Zed IDE settings

Created `.zed/settings.json` with all the settings from
`.vscode/settings.json`.

Author: ChaiTRex

.zed/settings.json

@@ -0,0 +1,68 @@
+{
+  "format_on_save": "on",
+  "lsp": {
+    "rust-analyzer": {
+      "initialization_options": {
+        "diagnostics": {
+          // in case rustc.source is disabled for performance reasons; disable the errors about this
+          "disabled": ["unresolved-extern-crate", "unresolved-macro-call"]
+        },
+        "rustc": {
+          "source": "discover"
+        },
+        "imports": {
+          "granularity": {
+            "enforce": true,
+            "group": "module"
+          },
+          "prefix": "crate"
+        },
+        "cargo": {
+          "features": ["unstable-features"]
+        },
+        "linkedProjects": [
+          "./Cargo.toml",
+          "./build_system/Cargo.toml",
+          {
+            "crates": [
+              {
+                "root_module": "./example/mini_core.rs",
+                "edition": "2018",
+                "deps": [],
+                "cfg": []
+              },
+              {
+                "root_module": "./example/mini_core_hello_world.rs",
+                "edition": "2018",
+                "deps": [
+                  {
+                    "crate": 0,
+                    "name": "mini_core"
+                  }
+                ],
+                "cfg": []
+              },
+              {
+                "root_module": "./example/mod_bench.rs",
+                "edition": "2018",
+                "deps": [],
+                "cfg": []
+              }
+            ]
+          },
+          {
+            "sysroot_src": "./build/stdlib/library",
+            "crates": [
+              {
+                "root_module": "./example/std_example.rs",
+                "edition": "2015",
+                "deps": [],
+                "cfg": []
+              }
+            ]
+          }
+        ]
+      }
+    }
+  }
+}