Add Termux install documentation

Problem: The Termux install is new and exciting and there isn't any
documentation on how to experiment with it.

Solution: Add some documentation like we've done with systemd and
Docker so that we can collaborate and figure it out in the repo!

.cspell.json

@@ -10,13 +10,19 @@
     "Machinekit",
     "OSSEC",
     "Pieter",
+    "Termux",
+    "autoconf",
+    "automake",
     "backlinks",
     "christianbundy",
     "dogfood",
     "hyperaxe",
     "hyperscript",
+    "libsodium",
+    "libtool",
     "manyverse",
     "minlength",
+    "mkdir",
     "monokai",
     "msgs",
     "multiserver",

docs/install.md

@@ -8,6 +8,8 @@ If you want to run Oasis in the background, see [`with-systemd.md`](./with-syste
 
 If you want to run Oasis in a container, see [`with-docker.md`](./with-docker.md).
 
+If you want to run Oasis on Android via Termux, see [`with-termux.md`](./with-termux.md).
+
 ## Download
 
 ### HTTPS

docs/with-termux.md

@@ -0,0 +1,44 @@
+# With Termux
+
+**Warning:** Experimental.
+
+Use [Termux](https://termux.com/) to run Oasis on Android.
+
+Please note that this is very experimental and very slow.
+
+## Build
+
+Copy and paste the commands below into your terminal and run them.
+
+```shell
+# Install dependencies, some are optional (in case you need to build from source)
+pkg install \
+  autoconf \
+  automake
+  git \
+  libsodium \
+  libtool \
+  make \
+  nodejs \
+  python
+
+# Allow global npm dependencies
+mkdir ~/.npm-global
+npm config set prefix '~/.npm-global'
+echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.profile
+source ~/.profile
+
+# Upgrade npm
+npm install -g npm
+
+# Install Oasis
+npm --global install --no-optional 'fraction/oasis#semver:*'
+```
+
+## Run
+
+Oasis should open in your browser at http://localhost:3000 after you run:
+
+```
+oasis
+```