booklet Fortran 95 features (#542)

* fix(object_based_programming_techniques.md): correct typos

A correction based on Beliavsky's reading.[1]

[1] #526

Signed-off-by: Norwid Behrnd <[email protected]>

* feat(f95_features.md): initiate work

Based on a request on fortran-lang.org,[1] work for a new
booklet for the learning section of fortran-lang.org about
the features of Fortran 95 starts.

The initial step was to fetch the source code (mediawiki synatax)
which was converted with Pandoc to GitHub flavored Markdown where
possible.  This was not possible for the trailing bibliography
section of the Wikipedia article (hence left as such in a fenced
code block), which however is more an optional "for an additional
read, consult ..." rather than a specific literature reference to
a particular keyword, or phrase.

While GitHub flavored Markdown isn't (yet) MyST Markdown flavor
required, it is close enough for the manual edit ahed.  Equally
a TODO is to build a multipage booklet, i.e. an `index.md` and
individual Markdown files about each chapter; this gradually
removes `f95_features.md` as an intermediate container file.

[1] https://fortran-lang.discourse.group/t/fortran-95-language-features/9263

Signed-off-by: Norwid Behrnd <[email protected]>

* add reference to "root version" of the booklet

Added an explicit note about the last commit (on side of Wikipedia)
the source of this booklet is about.

Signed-off-by: Norwid Behrnd <[email protected]>

* adjust code fences to f90

Throughout the source file (and equally in the mediawiki file),
the label of the code fences was `fortran`.  Because the file is
about Fortran 95, it was updated by

```bash
sed 's/``` fortran/```f90/' f95_features.md > temp.txt
mv temp.text f95_features.md
rm temp.txt
```

Signed-off-by: Norwid Behrnd <[email protected]>

* install index.md

Creation of the index.md file, already anticipating the first
chapter to be added.  Corresponding cut in the container file.

* update index of learn.md

The index of booklets in `learn.md` was amended by a link about
the new booklet under construction.

Signed-off-by: Norwid Behrnd <[email protected]>

* language_elements.md: lint with mdl

Linting with markdownlint (version 0.13.0) as packaged by Debian
Linux[1] except for any kind of links, tables and checks on
snippets of Fortran.

[1] https://tracker.debian.org/pkg/ruby-mdl

Signed-off-by: Norwid Behrnd <[email protected]>

* add bibliography.md

This copies the mediawiki source code block of the Wikipedia
article's bibliography.  It will be edited after the other
sections are revised.

Signed-off-by: Norwid Behrnd <[email protected]>

* detailed revision

Markdown files were edited for a more readable syntax; the
cross-referencing to other sections of the same, or other
Markdown files revised (and checked with the `#build_preview`
robot provide by https://github.com/fortran-lang/webpage/).

This squashes multiple (iterative) individual commits into a
single one.

Signed-off-by: Norwid Behrnd <[email protected]>

* correction of typos

* Update data/learning.yml

Co-authored-by: Copilot <[email protected]>

* Update data/learning.yml

Co-authored-by: Copilot <[email protected]>

* Update source/learn/f95_features/array_handling.md

Co-authored-by: Copilot <[email protected]>

* Update source/learn/f95_features/pointers.md

Co-authored-by: Copilot <[email protected]>

* Apply suggestion from @henilp105

---------

Signed-off-by: Norwid Behrnd <[email protected]>
Co-authored-by: Henil Panchal <[email protected]>
Co-authored-by: Copilot <[email protected]>

Author: 3 people

data/learning.yml

@@ -286,6 +286,23 @@ books:
       - /learn/oop_features_in_fortran/object_oriented_programming_techniques
       - /learn/oop_features_in_fortran/performance_and_ease_of_use
 
+  - title: Fortran 95 language features
+    description: Wikipedia's article about the Fortran 95 standard
+    category: Fortran Documentation
+    link: /learn/f95_features
+    pages:
+      - /learn/f95_features/
+      - /learn/f95_features/language_elements
+      - /learn/f95_features/expressions_and_assignments
+      - /learn/f95_features/control_statements
+      - /learn/f95_features/program_units_and_procedures
+      - /learn/f95_features/array_handling
+      - /learn/f95_features/pointers
+      - /learn/f95_features/intrinsic_procedures
+      - /learn/f95_features/data_transfer
+      - /learn/f95_features/operations_on_external_files
+      - /learn/f95_features/bibliography
+
 # Web links listed at the bottom of the 'Learn' landing page
 #
 reference-links:

source/learn.md

@@ -214,4 +214,5 @@ learn/best_practices/index
 learn/intrinsics/index
 learn/rosetta_stone
 learn/oop_features_in_fortran/index
+learn/f95_features/index
 :::