Improve documentation (#349)

* Improve documentation content
* Improve documentation style

docs/docs/dev/_category_.json

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+{
+  "label": "Development",
+  "position": 2
+}

docs/docs/dev/architecture.mdx

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+---
+sidebar_custom_props:
+  icon: TbApps
+---
+
+# Architecture
+
+
+import ThemedImage from '@theme/ThemedImage';
+
+<ThemedImage
+  alt="App Architecture"
+  sources={{
+    light: '/img/architecture-light.png',
+    dark: '/img/architecture-dark.png',
+  }}
+/>
+
+

docs/docs/dev/glossary.mdx

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+---
+sidebar_custom_props:
+  icon: TbVocabulary
+---
+# Glossary
+
+### Workspace
+A workspace usually represents a company using Twenty.  
+It's attached to a single domain name, which is usually the domain name you company uses for your employee email addresses.
+
+### Company & People
+They are the two fundamental type of records that the CRM is built around.  
+A company represents a business or an organization. And People represents an individual you are doing business with or would like to do business with.
+
+### Pipelines
+A pipeline is a way to track a business process.  
+Pipelines are categorized within a module and have stages.  
+A module is the business characterizations of your process (e.g. sales, recruiting).  
+Stages maps the steps in your process (e.g. new, ongoing, won, lost)

docs/docs/dev/workflows.mdx

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+---
+sidebar_custom_props:
+  icon: TbTopologyStar
+---
+# Workflows
+
+The following steps assume that you have installed and configure the project with Docker.
+
+## IDE Setup
+
+If you are using VSCode, please use the `Dev Containers` extension to open the project in a container.
+This will allow you to run Visual Studio on top of the docker container.
+
+## Front tests
+
+Run tests: `make front-test`
+Run coverage: `make front-coverage`
+Run storybook: `make front-storybook`
+
+## Running commands
+If you are using Docker install, make sure to ssh in the docker container during development to execute commands.
+You can use `Makefile` to help you do this: `make sh` will open a CLI in the docker container and commands such as `make front-test` have been setup to be executed in the container.