Documentation: Use unified license boilerplate

Signed-off-by: Masanori Ogino <mogino@acm.org>

Documentation/historical/hinsi.ms

@@ -1,3 +1,4 @@
+.\" SPDX-License-Identifier: MIT-open-group
 .\"
 .\" Copyright (c) 1991-1994  Sony Corporation
 .\"
@@ -25,12 +26,6 @@
 .\" or other dealings in this Software without prior written authorization
 .\" from Sony Corporation.
 .\"
-.\"Author: Noriyuki Hosoe, Sony Corporation
-.\"
-.\"$SonyRCSfile: hinsi.ms,v $
-.\"$SonyRevision: 1.1 $
-.\"$SonyDate: 1994/06/03 08:00:46 $
-.\"
 .TL
 \fBsj3serv\fP で使用される品詞
 .RS

Documentation/historical/makedict.ms

@@ -1,3 +1,4 @@
+.\" SPDX-License-Identifier: MIT-open-group
 .\"
 .\" Copyright (c) 1991-1994  Sony Corporation
 .\"
@@ -25,12 +26,6 @@
 .\" or other dealings in this Software without prior written authorization
 .\" from Sony Corporation.
 .\"
-.\"Author: Noriyuki Hosoe, Sony Corporation
-.\"
-.\"$SonyRCSfile: makedict.ms,v $
-.\"$SonyRevision: 1.1 $
-.\"$SonyDate: 1994/06/03 08:00:47 $
-.\"
 .TL
 辞書生成ツール makedict
 .RS

Documentation/historical/sj3.1

@@ -1,3 +1,4 @@
+.\" SPDX-License-Identifier: MIT-open-group
 .\"
 .\" Copyright (c) 1991-1994  Sony Corporation
 .\"
@@ -25,11 +26,6 @@
 .\" or other dealings in this Software without prior written authorization
 .\" from Sony Corporation.
 .\"
-.\"$SonyRCSfile: sj3.1,v $
-.\"$SonyRevision: 1.1 $
-.\"$SonyDate: 1994/06/03 08:00:50 $
-.\"
-.\" Japanese input frontend processor
 .TH SJ3 1 "October 1990"
 .SH 名称
 sj3 \- 日本語入力フロントエンドプロセッサ

Documentation/historical/sj3dic.1

@@ -1,4 +1,4 @@
-.\"
+.\" SPDX-License-Identifier: MIT-open-group
 .\" Copyright (c) 1991-1994  Sony Corporation
 .\"
 .\" Permission is hereby granted, free of charge, to any person obtaining
@@ -25,12 +25,6 @@
 .\" or other dealings in this Software without prior written authorization
 .\" from Sony Corporation.
 .\"
-.\"Author: Noriyuki Hosoe, Sony Corporation
-.\"
-.\"$SonyRCSfile: sj3dic.1,v $
-.\"$SonyRevision: 1.1 $
-.\"$SonyDate: 1994/06/03 08:00:51 $
-.\"
 .TH SJ3DIC 1
 .SH 名称
 sj3dic \- sj3 ユーザ辞書メンテナンスツール

Documentation/historical/sj3lib.ms

@@ -1,3 +1,4 @@
+.\" SPDX-License-Identifier: MIT-open-group
 .\"
 .\" Copyright (c) 1991-1994  Sony Corporation
 .\"
@@ -25,13 +26,6 @@
 .\" or other dealings in this Software without prior written authorization
 .\" from Sony Corporation.
 .\"
-.\"Author: Noriyuki Hosoe, Sony Corporation
-.\"Modifier: Nobuyuki Tanaka, Sony Corporation
-.\"
-.\"$SonyRCSfile: sj3lib.ms,v $
-.\"$SonyRevision: 1.1 $
-.\"$SonyDate: 1994/06/03 08:00:48 $
-.\"
 .TL
 sj3lib ライブラリ
 .AB

Documentation/historical/sj3mkdic.1

@@ -1,3 +1,4 @@
+.\" SPDX-License-Identifier: MIT-open-group
 .\"
 .\" Copyright (c) 1991-1994  Sony Corporation
 .\"
@@ -25,10 +26,6 @@
 .\" or other dealings in this Software without prior written authorization
 .\" from Sony Corporation.
 .\"
-.\"$SonyRCSfile: sj3mkdic.1,v $
-.\"$SonyRevision: 1.2 $
-.\"$SonyDate: 1996/09/05 12:08:20 $
-.\"
 .TH SJ3MKDIC 1
 .SH 名前
 \f4sj3mkdic\f1 \- sj3 辞書変換ツール

Documentation/historical/sj3serv.1

@@ -1,3 +1,4 @@
+.\" SPDX-License-Identifier: MIT-open-group
 .\"
 .\" Copyright (c) 1991-1994  Sony Corporation
 .\"
@@ -25,13 +26,6 @@
 .\" or other dealings in this Software without prior written authorization
 .\" from Sony Corporation.
 .\"
-.\"Author: Noriyuki Hosoe, Sony Corporation
-.\"
-.\"$SonyRCSfile: sj3serv.1,v $
-.\"$SonyRevision: 1.1 $
-.\"$SonyDate: 1994/06/03 08:00:52 $
-.\"
-.\" Server of Japanese input frontent processor
 .TH SJ3SERV 1 "October 1990"
 .SH 名称
 sj3serv \- 仮名漢字変換サーバ

Documentation/historical/sj3serv.ms

@@ -1,3 +1,4 @@
+.\" SPDX-License-Identifier: MIT-open-group
 .\"
 .\" Copyright (c) 1991-1994  Sony Corporation
 .\"
@@ -25,13 +26,6 @@
 .\" or other dealings in this Software without prior written authorization
 .\" from Sony Corporation.
 .\"
-.\"Author: Noriyuki Hosoe, Sony Corporation
-.\"Modifier: Nobuyuki Tanaka, Sony Corporation
-.\"
-.\"$SonyRCSfile: sj3serv.ms,v $
-.\"$SonyRevision: 1.1 $
-.\"$SonyDate: 1994/06/03 08:00:49 $
-.\"
 .TL
 仮名漢字変換サーバ sj3serv
 .SH