Added further dvc notes

dvc.md

@@ -1,7 +1,18 @@
 # DVC Notes
 Notes on how to accomplish various operation using DVC. Most of these are just distilled notes from the [DVC documentation](https://dvc.org/doc).
 
-## Setting up the repository
+## Installation
+DVC can be installed using `pip`, this will provide the basic CLI needed to execute commands with DVC:
+```shell
+$ pip install dvc
+```
+As well as the main package you will also need to install a package to work with the particular remote that is intended to store the data files tracked by dvc e.g. to work with dvc data stored in an S3 bucket:
+```shell
+$ pip install dvc[s3]
+```
+Hopefully if working with an existing repo the `requirements.txt` will contain the appropriate package for dvc tracked data.
+
+## Setting up a new repository
 To set up a git repository to track any data files using DVC use `dvc init` in the repository's directory, then `dvc remote add` to add a remote store to for your DVC tracked data e.g.
 ```shell
 $ dvc init
@@ -11,13 +22,30 @@ This will initialise the repository for use with DVC and setup a `remote` called
 
 You will also see a `.dvc/` directory and a `.dvcignore` file which you should add to you version controlled files.
 
+## Cloning a repository
+When cloning a repository that is set up with data tracked by dvc, use `dvc pull` to download the data files tracked by dvc from the remote:
+```shell
+$ git clone [email protected]:NERC-CEH/llm-eval.git
+$ cd llm-eval
+$ dvc pull
+```
+
 ## Making changes
 To make changes to your data use `dvc add` on the local file and then use `dvc push` to push to the remote store. It is then important to commit the `.dvc` object to git that is setup to track this file as well e.g.
 ```shell
 $ dvc add data.csv
 $ dvc push
 $ git commit data.csv.dvc -m 'Updated data file'
 ```
+`data.csv.dvc` is a place holder that dvc creates to tell it about the files/folder being tracked. This place holder will be tracked by git and the actual data tracked by dvc.
+
+### Moving data from git to dvc
+Any files or folders that you add to dvc must not be tracked by git. To switch from tracking a file with git to dvc, first untrack it with git:
+```shell
+$ git rm --cached data.csv
+```
+then follow the steps above to add the file(s) to be tracked by dvc.
+
 > Note: Whilst `dvc` commands seem to somewhat mirror `git` commands, there doesn't seem to be quite the same concept of a staging area. I would suggest that `dvc add` is more like an amalgamation (in DVC) of `git add` + `git commit`.
 
 ## Checking out versions