docs: use relative links (#2976)

Signed-off-by: Jinzhe Zeng <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

doc/getting-started/quick_start.ipynb

@@ -102,8 +102,7 @@
    "metadata": {},
    "source": [
     "## General Introduction\n",
-    "This tutorial will introduce you to the basic usage of the DeePMD-kit, taking a gas phase methane molecule as an example. [DeePMD-kit's documentation](https://docs.deepmodeling.org/projects/deepmd/ \n",
-    ") is recommended as the complete reference.\n",
+    "This tutorial will introduce you to the basic usage of the DeePMD-kit, taking a gas phase methane molecule as an example. [DeePMD-kit's documentation](../index.rst) is recommended as the complete reference.\n",
     "\n",
     "The DP model is generated using the DeePMD-kit package (v2.1.5). The training data is converted into the format of DeePMD-kit using a tool named dpdata (v0.2.14). \n",
     "\n",
@@ -129,7 +128,7 @@
    "id": "209c5dd7-983a-468e-9406-652ade04be91",
    "metadata": {},
    "source": [
-    "Folder `abacus_md` is obtained by performing ab-initio molecular dynamics with ABACUS. Detailed instructions on ABACUS can be found in its [document](https://abacus.deepmodeling.com/en/latest/). "
+    "Folder `abacus_md` is obtained by performing ab-initio molecular dynamics with ABACUS. Detailed instructions on ABACUS can be found in its [document](https://abacus.deepmodeling.com/). "
    ]
   },
   {
@@ -456,7 +455,7 @@
    "id": "7b0edb0f-df47-4e6c-8c37-5f32c4bd6b39",
    "metadata": {},
    "source": [
-    "More detailed docs about Data conversion can be found [here](https://docs.deepmodeling.org/projects/deepmd/en/master/data/data-conv.html)."
+    "More detailed docs about Data conversion can be found [here](../data/data-conv.md)."
    ]
   },
   {