Remove other files for now and add dev mode to menu

_data/sidebar.yml

@@ -1,3 +1,5 @@
+Getting started:
+  - Dev mode: /docs/getting-started/dev-mode
 Install and build:
   - Downloads: /downloads
   - Installing Ethereum: /docs/Building-Ethereum

docs/_getting-started/ns.md

@@ -1,47 +0,0 @@
-<!-- TODO: Read more -->
-
-## Next steps
-
-<!-- I like the idea of having a Getting started section. You may want to describe a few ways to get your feet wet with Geth (fast sync with a test net, dev mode, start a private network). -->
-
-### Fast sync a test network
-
-<!-- TODO: What happens if you don't specify? -->
-
-You learned about the `--syncmode` argument above, but you can also specify the network to sync with, by adding it as an argument. For example to fast sync with the Rinkeby test network:
-
-```shell
-geth --syncmode "fast" --rinkeby
-```
-
-To check the status of the sync, open another terminal, attach to the geth process, and open a console with the command below:
-
-<!-- TODO: Figuring out what to attach to seems difficult -->
-
-```shell
-geth attach ipc:{FILL_THIS}
-```
-
-Then at the `>` prompt, run the command below to the current state of the sync operation:
-
-```shell
-eth.syncing
-```
-
-## Dev mode
-
-Geth has a development mode which sets up a single node Ethereum test network along with a number of options optimized for local development. Enable it with the `--dev` argument.
-
-```shell
-geth --dev
-```
-
-<!-- TODO: Figuring out what to attach to seems difficult -->
-
-```shell
-geth attach ipc:{FILL_THIS}
-```
-
-<!-- TODO: Then? -->
-
-## Start a private network

docs/_getting-started/private-network.md

@@ -1,5 +0,0 @@
----
-title: Start a private network
----
-
-<!-- TODO: Already a couple of overlapping posts -->