[FDS-2449] Lock sphinx version and update poetry.lock (#1530)

Also install `typing-extensions` in the build

.readthedocs.yml

@@ -7,14 +7,15 @@ version: 2
 
 # Set the version of Python and other tools you might need
 build:
-  os: ubuntu-20.04
+  os: ubuntu-22.04
   tools:
     python: "3.9"
   jobs:
     post_install:
       - pip install poetry==1.3.0
       - poetry config virtualenvs.create false
-      - poetry install --with doc
+      - poetry install --all-extras
+      - pip install typing-extensions==4.12.2
     #Poetry will install my dependencies into the virtualenv created by readthedocs if I set virtualenvs.create=false
     # You can also specify other tool versions:
     # nodejs: "16"

README.md

@@ -270,12 +270,17 @@ poetry debug info
 
 Before you begin, make sure you are in the latest `develop` of the repository.
 
-The following command will install the dependencies based on what we specify in the `poetry.lock` file of this repository. If this step is taking a long time, try to go back to Step 2 and check your version of `poetry`. Alternatively, you can try deleting the lock file and regenerate it by doing `poetry install` (Please note this method should be used as a last resort because this would force other developers to change their development environment)
+The following command will install the dependencies based on what we specify in the `poetry.lock` file of this repository (which is generated from the libraries listed in the `pyproject.toml` file). If this step is taking a long time, try to go back to Step 2 and check your version of `poetry`. Alternatively, you can try deleting the lock file and regenerate it by doing `poetry lock` (Please note this method should be used as a last resort because this would force other developers to change their development environment).
 
 ```
-poetry install --all-extras
+poetry install --with dev,doc
 ```
 
+This command will install:
+* The main dependencies required for running the package.
+* Development dependencies for testing, linting, and code formatting.
+* Documentation dependencies such as `sphinx` for building and maintaining documentation.
+
 ### 5. Set up configuration files
 
 The following section will walk through setting up your configuration files with your credentials to allow for communication between `schematic` and the Synapse API.