docs: add MFS API (#1426)

License: MIT
Signed-off-by: Alan Shaw <[email protected]>

Author: alanshaw

README.md

@@ -356,15 +356,30 @@ The core API is grouped into several areas:
 #### `Files`
 
 - [files](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md)
-  - [`ipfs.files.add(data, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/FILES.md#add)
-  - [`ipfs.files.addReadableStream([options])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/FILES.md#addreadablestream)
-  - [`ipfs.files.addPullStream([options])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/FILES.md#addpullstream)
-  - [`ipfs.files.cat(ipfsPath, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/FILES.md#cat)
-  - [`ipfs.files.catReadableStream(ipfsPath, [options])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/FILES.md#catreadablestream)
-  - [`ipfs.files.catPullStream(ipfsPath, [options])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/FILES.md#catpullstream)
-  - [`ipfs.files.get(ipfsPath, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/FILES.md#get)
-  - [`ipfs.files.getReadableStream(ipfsPath, [options])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/FILES.md#getreadablestream)
-  - [`ipfs.files.getPullStream(ipfsPath, [options])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/FILES.md#getpullstream)
+  - [`ipfs.files.add(data, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesadd). Alias to `ipfs.add`.
+  - [`ipfs.files.addPullStream([options])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesaddpullstream)
+  - [`ipfs.files.addReadableStream([options])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesaddreadablestream)
+  - [`ipfs.files.cat(ipfsPath, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filescat). Alias to `ipfs.cat`.
+  - [`ipfs.files.catPullStream(ipfsPath, [options])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filescatpullstream)  
+  - [`ipfs.files.catReadableStream(ipfsPath, [options])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filescatreadablestream)
+  - [`ipfs.files.get(ipfsPath, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesget). Alias to `ipfs.get`.
+  - [`ipfs.files.getPullStream(ipfsPath, [options])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesgetpullstream)  
+  - [`ipfs.files.getReadableStream(ipfsPath, [options])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesgetreadablestream)
+  - [`ipfs.ls(ipfsPath, [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#ls)
+  - [`ipfs.lsPullStream(ipfsPath)`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#lspullstream)
+  - [`ipfs.lsReadableStream(ipfsPath)`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#lsreadablestream)
+  - [MFS (mutable file system) specific](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#mutable-file-system)
+    - [`ipfs.files.cp([from, to], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filescp)
+    - [`ipfs.files.flush([path], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesflush)
+    - [`ipfs.files.ls([path], [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesls)
+    - [`ipfs.files.mkdir(path, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesmkdir)
+    - [`ipfs.files.mv([from, to], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesmv)
+    - [`ipfs.files.read(path, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesread)
+    - [`ipfs.files.readPullStream(path, [options])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesreadpullstream)
+    - [`ipfs.files.readReadableStream(path, [options])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesreadreadablestream)
+    - [`ipfs.files.rm(path, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesrm)
+    - [`ipfs.files.stat(path, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#filesstat)
+    - [`ipfs.files.write(path, content, [options], [callback])`](https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#fileswrite)
 
 - [block](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/BLOCK.md)
   - [`ipfs.block.get(cid, [options, callback])`](https://github.com/ipfs/interface-ipfs-core/tree/master/SPEC/BLOCK.md#get)