Recommend deno install -g

In Deno 2.0, `deno install` seems to default to npm-like project
installation. Closes #338.

README.md

@@ -22,7 +22,7 @@ Install the Tools
 You will want the IR interpreter, which uses [Deno][].
 Just type this:
 
-    $ deno install brili.ts
+    $ deno install -g brili.ts
 
 As Deno tells you, you will then need to add `$HOME/.deno/bin` to [your `$PATH`][path].
 You will then have `brili`, which takes a Bril program as JSON on stdin and executes it.

docs/tools/brilck.md

@@ -10,7 +10,7 @@ Install
 The `brilck` tool uses [Deno][].
 Type this:
 
-    $ deno install brilck.ts
+    $ deno install -g brilck.ts
 
 If you haven't already, you will then need to add `$HOME/.deno/bin` to [your `$PATH`][path].
 

docs/tools/interp.md

@@ -13,7 +13,7 @@ Install
 To use the interpreter, you will need [Deno][].
 Just run:
 
-    $ deno install brili.ts
+    $ deno install -g brili.ts
 
 As Deno tells you, you will then need to add `$HOME/.deno/bin` to [your `$PATH`][path].
 

docs/tools/ts2bril.md

@@ -13,7 +13,7 @@ Install
 The TypeScript compiler uses [Deno][].
 Type this:
 
-    $ deno install --allow-env --allow-read ts2bril.ts
+    $ deno install -g --allow-env --allow-read ts2bril.ts
 
 If you haven't already, you will then need to add `$HOME/.deno/bin` to [your `$PATH`][path].