[doc] #66: fix typos in the README.md

README.md

@@ -30,7 +30,7 @@ You can install DuniterPy and its dependencies with the following command:
 pip3 install duniterpy --user
 ```
 
-## Install the development environement
+## Install the development environment
 - Install [Poetry](https://poetry.eustace.io):
 ```bash
 curl -sSL https://raw.githubusercontent.com/sdispater/poetry/master/get-poetry.py | python --preview
@@ -78,7 +78,7 @@ poetry run python examples/request_data.py
 
 * Install dev dependencies
 ```bash
-poetry instal
+poetry install
 ```
 
 * Check static typing with [mypy](http://mypy-lang.org/)
@@ -105,7 +105,7 @@ Change and commit and tag the new version number (semantic version number)
 
 Build the PyPi package in the `dist` folder
 ```bash
-Noetry build
+Poetry build
 ```
 
 Deploy the package to PyPi test repository (prefix the command with a space in order for the shell not to save in its history system the command containing the password)