docs: refresh the stale Python and Node binding READMEs

The Python binding README still advertised "63 indicators across four
families" with the pre-restructure five-group taxonomy, missing the eight
indicators added since. Update it to "71 indicators across eight families"
with the catalogue grouped to match the main README.

The Node binding README referred to the package as @wickra/wickra in its
title, install command and import example; the published package is named
wickra (per bindings/node/package.json). Correct all three.

bindings/node/README.md

@@ -1,4 +1,4 @@
-# @wickra/wickra
+# wickra
 
 Node.js bindings for the Wickra streaming-first technical indicators library.
 
@@ -7,7 +7,7 @@ Node.js bindings for the Wickra streaming-first technical indicators library.
 Once published, install per platform via the precompiled native package:
 
 ```bash
-npm install @wickra/wickra
+npm install wickra
 ```
 
 ## Build from source
@@ -26,7 +26,7 @@ produces a `wickra.<platform>-<arch>.node` binary in the package root that
 ## Usage
 
 ```js
-import { SMA, RSI, MACD, version } from '@wickra/wickra';
+import { SMA, RSI, MACD, version } from 'wickra';
 
 console.log('wickra', version());