diff --git a/docs/developer_guide.md b/docs/developer_guide.md
new file mode 100644
index 0000000..bca68f8
--- /dev/null
+++ b/docs/developer_guide.md
@@ -0,0 +1,83 @@
+# Developer Guide
+
+This document provides everything you need to know about the development of RenderCV.
+
+## Getting Started
+
+1. Ensure that you have Python version 3.10 or higher.
+
+2. Then, clone the repository recursively (because TinyTeX is being used as a submodule) with the following command.
+```bash
+git clone --recursive https://github.com/sinaatalay/rendercv.git
+```
+
+3. Go to the `rendercv` directory.
+```bash
+cd rendercv
+```
+
+4. Create a virtual environment.
+```bash
+python -m venv .venv
+```
+
+5. Activate the virtual environment.
+
+    === "Windows (PowerShell)"
+        ```powershell
+        .venv\Scripts\Activate.ps1
+        ```
+    === "MacOS/Linux"
+        ```bash
+        source .venv/bin/activate
+        ```
+
+6. Install the dependencies.
+```bash
+pip install .[docs,tests,dev]
+```
+
+## How RenderCV works?
+
+The flowchart below illustrates the general operations of RenderCV. A detailed documentation of the source code is available in the [reference](reference/index.md).
+
+```mermaid
+flowchart TD
+    A[YAML Input File] --parsing with ruamel.yaml package--> B(Python Dictionary)
+    B --validation with pydantic package--> C((Pydantic Object))
+    C --> D[LaTeX File]
+    C --> E[Markdown File]
+    E --markdown package--> K[HTML FIle]
+    D --TinyTeX--> L[PDF File]
+    L --PyMuPDF package--> Z[PNG Files]
+    AA[(Jinja2 Templates)] --> D
+    AA[(Jinja2 Templates)] --> E
+```
+
+## Writing Documentation
+
+The documentation's source files are located in the `docs` directory and it is built using the `mkdocs` package. To work on the documentation and see the changes in real-time, run the following command.
+
+```bash
+mkdocs serve
+```
+
+## Testing
+
+After updating the code, all tests should pass. To run the tests, use the following command.
+
+```bash
+pytest
+```
+
+### A note about `testdata` folder
+
+In some of the tests:
+
+- RenderCV generates an output with a sample input.
+- Then, the output is compared with a reference output, which has been manually generated and stored in `testdata`. If the files differ, the tests fail.
+
+
+When the `testdata` folder needs to be updated, it can be manually regenerated by setting `update_testdata` to `True` in `conftest.py` and running the tests.
+
+Whenever the `testdata` folder is generated, the files should be reviewed manually to ensure everything works as expected.
\ No newline at end of file
diff --git a/mkdocs.yaml b/mkdocs.yaml
index 3942631..35715a9 100644
--- a/mkdocs.yaml
+++ b/mkdocs.yaml
@@ -71,8 +71,12 @@ markdown_extensions:
       line_spans: __span
       pygments_lang_class: true
   - pymdownx.inlinehilite
-  - pymdownx.superfences
-  - pymdownx.extra
+  - pymdownx.extra:
+      pymdownx.superfences:
+        custom_fences:
+          - name: mermaid
+            class: mermaid
+            format: !!python/name:pymdownx.superfences.fence_code_format
   - pymdownx.tabbed: # content tabs
       alternate_style: true
   - toc:
diff --git a/rendercv/data_models.py b/rendercv/data_models.py
index 87ce5be..c2ee9a1 100644
--- a/rendercv/data_models.py
+++ b/rendercv/data_models.py
@@ -242,9 +242,7 @@ class EntryWithDate(RenderCVBaseModel):
         return date_string
 
 
-class PublicationEntry(EntryWithDate):
-    """This class is the data model of `PublicationEntry`."""
-
+class PublicationEntryBase(RenderCVBaseModel):
     title: str = pydantic.Field(
         title="Title of the Publication",
         description="The title of the publication.",
@@ -292,6 +290,12 @@ class PublicationEntry(EntryWithDate):
         return f"https://doi.org/{self.doi}"
 
 
+class PublicationEntry(EntryWithDate, PublicationEntryBase):
+    """This class is the data model of `PublicationEntry`."""
+
+    pass
+
+
 class EntryBase(EntryWithDate):
     """This class is the parent class of some of the entry types. It is being used
     because some of the entry types have common fields like dates, highlights, location,
@@ -565,7 +569,6 @@ class EntryBase(EntryWithDate):
 
 
 class NormalEntryBase(RenderCVBaseModel):
-
     name: str = pydantic.Field(
         title="Name",
         description="The name of the NormalEntry.",