[#253] clean up INSTALL.md

- Added `Install` section to group debian and rpm installs.
- Re-added `</br>`s -- they're used to break the `_Explanation:_` blocks
  to the next line. My personal preference is to _not_ use `</br>`s in
  docs, but i didn't want to change too many things here.
- Shortened titles `Add the repo to a Debian ...` and `... Fedora ...`
  to keep it super concise and decoupled from actual steps
- Some formatting best-practices
  - newlines between markdown blocks
  - indent code blocks that belong to bullet points to make sure
    that they are syntatically grouped (i.e. correct markdown 'DOM'
    hierarchy)
- sudo:
  - Removed `sudo` explanations. `apt/dnf/yum` will not run without, no
    need to explain.
  - added `sudo` to RPM instruction code blocks (just those two)
    for consistency, and also you can't run dnf/yum without root anyway.
- Made generic "Fedora based" instructions. Actually YUM/DNF-based,
  keeping it simple for now. Also name-dropped common distros for
  SEO/CTRL+F convenience
- Removed certain `Explanation` blocks for concision. Some are repeated,
  and some step titles are already self-explanatory

INSTALL.md

@@ -4,9 +4,11 @@
 
 These network support nodes are heavier than the node a user would establish on their phone in the form of a chat or social media application. A cloud based virtual private server (VPS), such as Digital Ocean Droplets or AWS EC2, with high bandwidth, processing resources, and uptime availability is crucial for building the fast, secure, and private routing that Veilid is built to provide.
 
-### Add the repo to a Debian based system and install a Veilid node
+## Install
 
-This is a multi-step process.
+### Debian
+
+Follow the steps here to add the repo to a Debian based system and install Veilid.
 
 **Step 1**: Add the GPG keys to your operating systems keyring.
 *Explanation*: The `wget` command downloads the public key, and the `sudo gpg` command adds the public key to the keyring.
@@ -15,52 +17,59 @@ This is a multi-step process.
 wget -O- https://packages.veilid.net/gpg/veilid-packages-key.public | sudo gpg --dearmor -o /usr/share/keyrings/veilid-packages-keyring.gpg
 ```
 
-**Step 2**: Identify your architecture
+**Step 2**: Identify your architecture<br />
 *Explanation*: The following command will tell you what type of CPU your system is running
 
 ```shell
 dpkg --print-architecture
 ```
 
-**Step 3**: Add Veilid to your list of available software.
+**Step 3**: Add Veilid to your list of available software.<br />
-*Explanation*: Using the command in **Step 2** you will need to run **one** of the following:
+*Explanation*: Use the result of your command in **Step 2** and run **one** of the following:
 
 - For **AMD64** based systems run this command:
 
-```shell
+  ```shell
-echo "deb [arch=amd64 signed-by=/usr/share/keyrings/veilid-packages-keyring.gpg] https://packages.veilid.net/apt stable main" | sudo tee /etc/apt/sources.list.d/veilid.list 1>/dev/null
+  echo "deb [arch=amd64 signed-by=/usr/share/keyrings/veilid-packages-keyring.gpg] https://packages.veilid.net/apt stable main" | sudo tee /etc/apt/sources.list.d/veilid.list 1>/dev/null
-```
+  ```
 
 - For **ARM64** based systems run this command:
 
-```shell
+  ```shell
-echo "deb [arch=arm64 signed-by=/usr/share/keyrings/veilid-packages-keyring.gpg] https://packages.veilid.net/apt stable main" | sudo tee /etc/apt/sources.list.d/veilid.list 1>/dev/null
+  echo "deb [arch=arm64 signed-by=/usr/share/keyrings/veilid-packages-keyring.gpg] https://packages.veilid.net/apt stable main" | sudo tee /etc/apt/sources.list.d/veilid.list 1>/dev/null
-```
+  ```
 
 *Explanation*:
 Each of the above commands will create a new file called `veilid.list` in the `/etc/apt/sources.list.d/`. This file contains instructions that tell the operating system where to download Veilid.
 
-**Step 4**: Refresh the package manager.
+**Step 4**: Refresh the package manager.<br />
-*Explanation*: This tells the `apt` package manager to rebuild the list of available software using the files in `/etc/apt/sources.list.d/` directory. This is invoked with "sudo" to grant superuser permission to make the changes.
+*Explanation*: This tells the `apt` package manager to rebuild the list of available software using the files in `/etc/apt/sources.list.d/` directory.
 
 ```shell
 sudo apt update
 ```
 
 **Step 5**: Install Veilid.
-*Explanation*: With the package manager updated, it is now possible to install Veilid! This is invoked with "sudo" to grant superuser permission to make the changes.
 
 ```shell
 sudo apt install veilid-server veilid-cli
 ```
 
-### Add the repo to a Fedora based system and install a Veilid node
+### RPM-based
+
+Follow the steps here to add the repo to
+RPM-based systems (CentOS, Rocky Linux, AlmaLinux, Fedora, etc.)
+and install Veilid.
 
 **Step 1**: Add Veilid to your list of available software.
-*Explanation*: With the package manager updated, it is now possible to install Veilid!
 
 ```shell
-yum-config-manager --add-repo https://packages.veilid.net/rpm/veilid-rpm-repo.repo
+sudo yum-config-manager --add-repo https://packages.veilid.net/rpm/veilid-rpm-repo.repo
+```
+**Step 2**: Install Veilid.
+
+```shell
+sudo dnf install veilid-server veilid-cli
 ```
 
 **Step 2**: Install Veilid.